BIOMOLECULES in ONE SHOT || Full Chapters || Class 12 BOARDS || PW

0:01Alright . So , hello everyone . How is

0:04everyone doing ? This is your Nikhil . So

0:05today , I have brought the last

0:07chemistry lecture for you in 12th Board

0:09Hackers . This is Biomolecules , and

0:11lecture number five for Organic , and in

0:13general . I think lecture number 10 for

0:16the whole of Chemistry . So , I think you

0:18will get this lecture on the same day

0:20as Amines , as far as I've been told . So

0:22, alright , keep doing the lectures . And

0:24keep going with the flow . You have

0:26already had four organic lectures

0:28before this . This is the last one in

0:29the series . This chapter is a bit

0:32different from your previous organic

0:34lectures . Okay ? In the sense that it

0:36has more of a theoretical part . Those

0:38of you who have taken biology will

0:39already have an idea about this . You

0:41have already studied this chapter

0:42before . For those from non-bio

0:44backgrounds , let me tell you . There is

0:46a bit more theoretical data in this .

0:47Okay ? So what I did is , you could call

0:50it a summary of the NCERT . I have

0:52prepared notes in a concise way . We

0:54will understand that only . Yes , in this

0:57particular chapter , you will have to

0:59revise NCERT to a great extent . Meaning

1:01, look at the class notes properly once

1:03. Yes , before watching the lecture ,

1:05download the notes . Keep the notes to

1:07the side and keep understanding what I

1:08am saying . Then , go through the NCERT

1:11repeatedly . If you do these two things

1:13and solve the PYQs , it will be very ,

1:16very easy . Okay ? So it is a somewhat

1:18theoretical chapter . Theory , theory ,

1:20theory is coming up again and again . So

1:21there is less stuff to understand here .

1:24I am telling you beforehand . Okay ? Just

1:25like we have done four chapters so far ,

1:28but okay , we will see whatever little

1:30conceptual idea is there . So this is a

1:32chapter that I would recommend you to

1:35revise properly one day before the exam

1:37. Okay ? Treat it just like you do

1:40Inorganic Chemistry . You will have to

1:42go through it repeatedly . As for your

1:45concern regarding the marathon , I will

1:47clear that up first . There is a

1:49constant demand from you guys for the

1:50marathon . Sir , questions , questions ,

1:51questions , we only want to do questions

1:53. Theory is done . So yes , the theory

1:55has been fully covered for you here in

1:57the classes . In the marathon , our

1:59primary focus will be on the questions .

2:02So , you will get a marathon session one

2:05day before the exam . And this marathon

2:07will be a session held the day before .

2:09In that session , we will cover all the

2:12most probable questions . We will look

2:15at the PYQs we left out , and some

2:17questions that I feel have a higher

2:19probability of appearing ; these will be

2:21the questions we discuss there . Okay ?

2:24So , now you will have more practice

2:26with questions . Yes , there will be a

2:28surprise for all of you . As of now ,

2:30well , I might as well just tell you

2:32what the surprise is . The CBSE sample

2:35paper , the one sample paper that comes

2:38from CBSE . We will have a discussion on

2:40that sample paper right here . Okay ? So ,

2:42we will also present that sample paper

2:44to you , provided they haven't changed

2:46it . Alright management , don't change

2:48that . So these are the two things we

2:50are planning for you on the 26th , I

2:53think . Okay ? Come on then , let's crush

2:56this session together ! And yes ,

2:58that’s all the talk . And yes , come

3:01out of the Physics shock because our

3:03paper now is Chemistry , and in

3:05Chemistry , we are fully targeting full

3:08marks . Okay ? Let's get started , ladies

3:10and gentlemen ; we have to read the

3:11whole chapter now . Look guys , we will

3:13study this in a flow . It will be in one

3:15single flow because it's a bit of a

3:16theoretical chapter . So , as I said ,

3:18download the notes and open them up .

3:20Match whatever slide is appearing with

3:22the notes and try to understand what I

3:24am saying . Okay ? Come on then , first of

3:27all , let's talk about carbohydrates . If

3:29I talk about carbohydrates , the initial

3:31definition was hydrates of carbon .

3:34Hydrates of carbon means water ,

3:36compounds of carbon with water . Huh ?

3:38Like glucose , it's a carbohydrate .

3:41Glucose , this is C6H12O6 , we will see

3:43its formula in a bit . We can represent

3:45it in this form , oh yes sir , we

3:47absolutely can . Look at this , it's

3:48clearly visible — six carbons and the

3:50water also six according to that .

3:52Similarly , the formula for fructose can

3:53also be set up this way . Look , so they

3:55said , man , such a setting is happening ,

3:57let's just do it . I mean , the

3:59definition also feels nice , really cute

4:01— let's make it ' hydrates of carbon ' ,

4:02right ? This was done earlier , this was

4:05done 800 years ago from today . Now the

4:08point is , is this definition correct ?

4:11Why , sir , why did you write ' initial ' ?

4:12No brother , there is some problem with

4:13this definition . The problem was that

4:15compounds like formaldehyde , it is an

4:17aldehyde . Everyone knows that . You can

4:19fit this into this definition too . One

4:21carbon , one water . Like we studied

4:23acetic acid , this too . Huh ? You can fit

4:25acetic acid into this definition as

4:27well . Now we have these compounds .

4:29Rhamnose , deoxyribose . Look at this .

4:31These are such compounds that are

4:33fitting into this definition quite

4:34strangely . Huh ? They are also coming

4:36into the same category . Carbohydrates .

4:38Being carbohydrates , they aren't able

4:39to fit into this category . Take a look .

4:41Huh ? Just look , is it fitting ? This is

4:43a carbohydrate . Is it fitting into this

4:45definition ? No brother . So this was the

4:48issue , that these people aren't even

4:50able to fit . And if they aren't able to

4:53fit , then buddy , there is some problem .

4:56Okay ? We cannot proceed with this

4:59definition . And if we can't , then what

5:01is its definition ? For that , you need

5:03to get a little bit of an idea . Of the

5:05structure of glucose and fructose . Look

5:07man , in front of us , this is the

5:08structure of glucose . This is the

5:10structure of fructose . Okay ? If you

5:12look , then this is your entire compound

5:14. How did this come , sir ? We will see ;

5:16the whole game depends on this . Let's

5:18focus here on glucose . You have an

5:21aldehyde . Okay ? And there are many

5:24hydroxyl groups . Hydroxyl means

5:26alcoholic groups . Okay ? Take a look .

5:28Here , like in glucose , this is

5:29happening . So it means I have multiple

5:31hydroxyl groups along with an aldehyde .

5:33Okay ? This can be it , or like if I talk

5:36about keto-fructose , then there is a

5:38ketone group and multiple hydroxyl

5:40groups . All this is coming to you . So I

5:42am understanding one thing , what are

5:44carbohydrates ? Basically , these are

5:47polyhydroxy , poly means more than one .

5:49Hydroxy means OH group . So polyhydroxy

5:52aldehyde or polyhydroxy ketone . This

5:56can be a carbohydrate . Or such

5:58compounds , for example , I take sucrose .

6:01When you put sucrose in water , after

6:03putting it in water , it undergoes

6:04hydrolysis reactions ; we have done many

6:06. So such compounds , that after putting

6:09them in water , you can make that thing .

6:11Okay ? Either you have a direct

6:13polyhydroxy aldehyde or polyhydroxy

6:15ketone , that is an option . Or generate

6:18it after putting it into water . So what

6:20do we call each of these compounds ,

6:22this one and that one ? We call them

6:24carbohydrates . That is its definition .

6:26The modern definition states

6:28carbohydrates are polyhydroxy aldehydes

6:30or ketones , or compounds that can form

6:33polyhydroxy aldehydes and ketones upon

6:35hydrolysis . Is this point clear ? I hope

6:38this is clear . Okay ? Let's move ahead .

6:41Next up . That is its classification .

6:44Look , you have monosaccharides ,

6:47oligosaccharides , and polysaccharides .

6:50What is it , basically ? It's the concept

6:52of putting it in water . If there is no

6:54hydrolysis after putting it in water ,

6:56it remains as it is . Like when you put

6:57glucose in water , it stays that way .

6:59Okay ? It doesn't undergo hydrolysis in

7:00the form of glucose . It doesn't break

7:02down further . So , what would we call

7:04such compounds ? Monosaccharides . So

7:06that is what is written , which does not

7:07hydrolyze further — glucose , fructose ,

7:09galactose , we will see many more later .

7:11Okay ? The second one , oligo , what does

7:13that mean ? One that creates two to ten

7:15units . If it creates two units , it's

7:17called a disaccharide . If it creates

7:19three units , it's called a

7:20trisaccharide . Four would be tetra , and

7:23so on . Okay ? So , which produces two to

7:25ten units upon hydrolysis . Okay ? Yes ,

7:28these disaccharides are important ones

7:30that we need to do . We don't need to

7:32worry about trisaccharides . Although I

7:33wrote it down for your reference , like

7:35raffinose . It's not that useful . You

7:36should know about disaccharides . And we

7:38need to remember this data . As I said ,

7:40this chapter is a bit about

7:41memorization . Sucrose is made of

7:43glucose plus fructose . Okay ? Exact

7:45structure , exact linkage , we have to do

7:47all of it . It is coming up ahead . Okay ?

7:49Maltose is made of glucose and glucose .

7:51Lactose is made of glucose and

7:53galactose . Okay ? Polysaccharides , which

7:55produce more than ten monosaccharide

7:57units upon hydrolysis . Starch ,

7:59cellulose , glucose . We will look into

8:01this . Okay ? So , basically the number of

8:04units . Call this one unit . For instance

8:06, call glucose one unit . If there is

8:07one unit , it’s mono , two is di , three

8:09is tri , and so on ; two to ten are

8:11oligosaccharides and more than ten we

8:14call polysaccharides . This is done . Now

8:17let's move to the next , that is its

8:19classification based on nature . One is

8:21sugar , the other is non-sugar . I think

8:24somewhere or other , we understand

8:25carbohydrates more as sugar . Right ? We

8:28call it sweet . Alright ? So , it's not

8:30necessary that every carbohydrate is

8:32sweet . Okay ? We have glucose , fructose ,

8:34sir , they are sweet . Yes , brother , not

8:37everything is . Okay ? So , something that

8:39is sweet in taste , like you say , falls

8:42into the sugar category . Generally , the

8:45non-sugar category has a bland taste .

8:47Okay ? Like , have you ever tasted a leaf

8:49, huh ? Sir , do you think we are donkeys

8:52? What do you call it , guys , do you

8:54think we are ? Huh ? Do we eat leaves ?

8:57Don't know . But if you ever taste it ,

8:59it is bland . Okay ? Because the

9:01cellulose concept comes into play there

9:02. Right ? So , I am not going towards

9:04that side . Let's come back to sugar .

9:07Like you've seen , you've seen sugar

9:09crystals , right ? They are crystalline .

9:11They mostly have a proper shape . Okay .

9:14Non-sugars are mostly amorphous ,

9:15amorphous meaning more like a powder or

9:17irregular shape , let's assume for now ,

9:18so don't worry too much about the solid

9:20state . Okay , so these are generally

9:22water-soluble , meaning if you put them

9:24in water , glucose , you've seen it

9:26dissolves in water , right ? Sweet in

9:28taste , I already told you , and most of

9:29your monosaccharides and

9:30oligosaccharides are what ? These are in

9:32the sugar categories . Whereas if you

9:35look at non-sugars , I gave you a very

9:36good example of cellulose , it is

9:38amorphous , water-insoluble , in water ,

9:39does a leaf ever just mix into water

9:41like that ? It doesn't , right ? Bland in

9:44taste , like polysaccharides , all of

9:46them are your non-sugars . So , this is

9:48what we need to understand here . After

9:50this , we come to the basis of the

9:52number of carbons , so how many carbons

9:54there are , that will decide . See , every

9:56carbohydrate is understood by ' ose ' , so

9:59whatever the carbohydrate is , it will

10:01have ' ose ' written at the end . Okay ?

10:04This ' ose ' is the suffix to designate a

10:07carbohydrate . Okay ? So , the idea is

10:09that if I have three carbons in it .

10:12Okay ? Then I will call it tri and then

10:15add ' ose ' . Because it is a carbohydrate

10:16, so ' ose ' makes it understood as a

10:18carbohydrate . Tri means there are three

10:19units . For four it's tetrose , for five

10:21pentose , for six hexose . So , you can

10:23denote carbohydrates in this way . Now ,

10:25carbohydrates are of two types . One

10:27that has an aldehyde , one that has a

10:28ketone . Glucose was your aldehyde one .

10:31Fructose was your ketone one . So , the

10:33ones with the aldehyde group will be

10:35called aldoses . The ones with the

10:37ketone group will be called ketoses . So

10:40sir , suppose I have a three-unit

10:42aldehyde , then I will add ' aldo ' before

10:44this triose , and if I get a three-unit

10:47ketone , what will I add ? Keto , yes . So ,

10:51aldose , ketose , and in the same way ,

10:53tetrose , four : aldo-tetrose ,

10:54keto-tetrose . And so on , it continues

10:57like this . Okay ? So , your glucose , sir ,

11:00let's talk about glucose ; it has an

11:02aldehyde group and it has six carbons .

11:05I showed you its structure once , so

11:07what will I call it ? Aldohexose . Got it

11:10? This is how the whole thing works . So

11:12, this is your classification based on

11:14the number . Okay ? Let's see one more

11:17classification . That is on the basis of

11:19reducing nature . Now , we saw this

11:21matter in the previous or the chapter

11:23before the last . That is , we performed

11:26some tests on aldehydes , ketones , and

11:28carboxylic acids . Okay ? So , in that , if

11:30we talk about reducing sugars , those

11:32sugars that give Tollen's , Fehling's ,

11:34and there is a Benedict's test . We

11:37don't need to worry about it . It is

11:38just like Fehling's , as of now . Okay ?

11:40If Tollen's , Fehling's , or Benedict's

11:42test . Okay ? These tests give a positive

11:44solution . Positive means if it is

11:46giving a Tollen's test , meaning it is

11:47happening , the result is appearing , the

11:49silver mirror is visible , then we call

11:51it a positive test . If their results

11:52are positive , then if these give

11:54positive results , we call it a reducing

11:56sugar . If their results do not come out

11:58positive , if these tests are negative ,

12:00we call it a non-reducing sugar . Now ,

12:02how do we find out ? The simple concept

12:05is that you check if a hemiacetal

12:07linkage is present inside it . Sir , how

12:09will we identify this hemiacetal

12:11linkage ? When we come to the structures

12:13, we will discuss this . As of now , if

12:15there is an option for a hemiacetal

12:17linkage , I told you about the

12:19hemiacetal group . It can be converted

12:21back to an aldehyde or ketone ,

12:23whichever aldehyde group is there . Okay

12:26? Based on that , we can revert that

12:28conversion . So , if a hemiacetal is

12:31present , then we will say that it could

12:33have a reducing nature . Because ,

12:36somewhere or other , who gives the test ?

12:38Who does this test come from ? Who gives

12:39Tollen's , Fehling's , and Benedict's ?

12:41Aldehydes used to give it , right ,

12:42generally for the most part . So , if it

12:44can regenerate into aldehydes , who can

12:46do that ? A hemiacetal can do it . So if

12:48a hemiacetal is present , you would call

12:50it a positive test . If you have a

12:52hemiacetal linkage absent , then we will

12:54call it a negative test . Now , sir , how

12:56do we see this ? I will tell you how to

12:57look for it . As of now , what are the

12:59examples ? All the monosaccharide units

13:01that you have . Okay ? They have this

13:04linkage present within them . So what we

13:06say is that , look , all of these are

13:08what ? These are reducing . Yes . Whereas ,

13:11if I talk about disaccharides , then

13:13what are they ? Maltose and lactose .

13:15What will these be ? They remain

13:17reducing . Similarly , all the

13:18polysaccharides in this , I will discuss

13:20them now . I will explain to you from

13:23the structure how it is becoming

13:24reducing or non-reducing . All of these

13:26that you , what do you call them ? I have

13:28already told you how to check for

13:29hemiacetal . What are the examples ? All

13:31polysaccharides have a C1 linkage . I

13:33will tell you what a C1 linkage is . If

13:35you are connected by a C1 linkage .

13:37Let's discuss that further . Remember

13:39the disaccharides . Sucrose is a

13:41non-reducing sugar . Now , this concept

13:43of sugar and non-sugar is a bit

13:45test-based . You have to look at the

13:47groups , look at the structures . So you

13:49will get a complete idea of this . Okay ?

13:51Now , come here , that is , method of

13:54preparation . If I do the method of

13:56preparation , they have given two direct

13:58reactions in NCERT . One is from cane

14:00sugar , that is sucrose . Okay ? This is

14:03sucrose . What happens if you put

14:05sucrose in water ? Hydrolysis will occur

14:07. Its hydrolysis , meaning it breaks

14:09down in water , so it splits into its

14:10units , glucose and fructose . Do you

14:12remember their optical activity ? We did

14:14it on day one in haloalkanes , optical

14:16activity . So actually , the angles they

14:19have , this sucrose shows an angle of

14:2166.5 ° . If you bring in glucose , it

14:24has + 52.5 ° . If you bring in fructose

14:27, it has -92 ° . So the idea is that if

14:30you talk about its rotation , man , this

14:32is a positive rotation . This is called

14:35dextrorotatory . Whereas , if I talk

14:37about their net rotation . Net of this

14:40and this , see their net rotation , this

14:42is in positive but that is in very high

14:44negative . So if you talk about net

14:47rotation , what is the net rotation ?

14:49This is coming out as levo . So it is

14:53levorotatory . So now the idea is that

14:55since this was your dextro . Levo means

14:58the one with the negative angle . So the

15:00total angle initially in sucrose goes

15:02from positive toward negative . So if

15:05the angle comes from positive toward

15:08negative . In such cases , what is the

15:10overall change ? Dextro-levo . This is

15:12called inversion of cane sugar . So in

15:14inversion of cane sugar , you are not

15:15physically rotating the sugar . Its

15:17angle is changing because sucrose is

15:19breaking into glucose and your fructose

15:21. I hope this is done . Yes . Now let's

15:25move to the next . Talking further after

15:27this , we come to this . That is starch

15:29and cellulose . Now , when we look at

15:31their structures , you will know how I

15:33make these from glucose . So don't worry

15:35about it for now . Technically , it would

15:37have been more sensible to do that at

15:38the end . So there's starch and

15:41cellulose . What do you need to do ? It

15:44is a polymer of glucose . Meaning , you

15:47have combined many glucose units to get

15:49this structure . So if you hydrolyze

15:52this structure . Right ? You have to

15:54provide some conditions . Two to three

15:55atmospheres , slightly high temperature ,

15:57and done in the presence of acid . When

15:59you do this , the entire units break

16:00down . So when the whole units start

16:02breaking , what will you get

16:03individually ? You will get glucose . So

16:05this is a polymer . How is the polymer

16:07formed ? I will show you later . Next , if

16:09I talk about the properties of glucose .

16:13Now look , there are very simple , small

16:15points inside this , but you have to

16:17grasp them all . I think you have

16:19understood the structure by now . Yes .

16:21In some books , this structure is also

16:23shown like this . The aldehyde on top .

16:25Right ? Look over here . OH will be

16:27denoted like this . This then here , then

16:30here , then here , and this is CH2OH . So

16:33in some places , your glucose is denoted

16:36in this way as well . It is nothing . A

16:38small line is drawn on the side where

16:39the OH is present . So this is the

16:41structure of glucose . In this , first

16:43this is important . First right , okay ?

16:47Then left , then right-right , then down .

16:49Okay ? So look at this structure . Draw

16:51it two or three times . You have to

16:53remember this . Okay ? Next , if I talk

16:55about aldohexose , this is an aldohexose

16:58. I already told you the structure . '

16:59Ose ' means it is a carbohydrate . Aldo

17:01hex . Hex means six . Aldo means aldehyde

17:04. So , a six-carbon carbohydrate with an

17:06aldehyde . This is your glucose . It is

17:09dextrose . All right ? Meaning , the

17:11positive optical rotation it shows , how

17:13much is it ? + 52.5 ° . So , how much is

17:16its optical rotation ? It remains

17:18positive . That is why it is called

17:20dextrose . It is a monomer of starch and

17:22cellulose . So basically , if you put

17:25starch or cellulose in water and

17:27hydrolyze it , you will get glucose .

17:29Monomer means the unit from which the

17:32entire polymer is formed . Most abundant

17:35organic compound . So that is a bit of a

17:37... right ? What do you call that factor ?

17:40It is a trivial fact . There is the fact

17:42that it is the most abundant organic

17:43compound you have . One point comes up

17:45regarding chiral centers : how many

17:46chiral centers are present ? I mentioned

17:47that back then as well . So look here ,

17:49all the stars drawn here , look at this

17:51one , it has four different units . It

17:52has four different units . So these are

17:55the four chiral centers present in your

17:57glucose . So this is its entire

17:59structure . This is how we can what ?

18:02Present it . So this is your complete

18:05bio-data of glucose . Now , the point

18:08comes up : sir , how did we dream this up

18:11? Right ? How are we so sure that its

18:13structure is somewhat like this ? It is

18:16a straight chain , not branched , there

18:17is an aldehyde group , not an acid group

18:19. How did we find this out ? There must

18:22be some reason . They must have said it

18:23after some thought . Huh ? So what is the

18:25reason for this ? Let us look at that .

18:27Look , first of all , a reaction was

18:29performed . Right ? That is the reaction

18:31with HI in red phosphorus . This is the

18:33daddy of reducing agents . Meaning , it

18:35performs intense reduction . Right ? It

18:37reduces everything . It does not like

18:39oxygen at all . Just like what happened

18:41to you guys today with Physics , just

18:43like that . The reaction you have after

18:45the exam is the reaction it has towards

18:47oxygen . It sees oxygen and blows it

18:48away . Look , aldehyde becomes methane .

18:51Yes , a methyl group appeared . OH

18:53becomes simple hydrogen . It means it

18:54wreaks havoc on oxygen completely .

18:56Wherever it sees oxygen , it finishes it

18:58off . It destroys it . It makes oxygen

19:00cry . So this has to be blown away . This

19:01has to be blown away . Right ? So now

19:04look , if I have given you this

19:05structure inside glucose , they were

19:08testing it . So they put glucose into

19:10red phosphorus , along with HI . Look ,

19:13bro , I am getting n-butane , 1 , 2 , 3 , 4 ,

19:155 , 6 sorry , I am getting n-hexane . So ,

19:19if you get n-hexane , then he thought , "

19:21Man , this is quite intense . " Meaning , I

19:25found out this much that no matter what

19:27, this glucose will have six carbons in

19:28a straight chain . This was the

19:30verification , so it is written , " This

19:33reaction proves that glucose has six

19:35carbon atoms in a straight chain . " So ,

19:37all the carbons are in a straight chain

19:39; for now , this much is known . Only

19:41from this reaction , there is no other

19:42pressure . This much is known as of now .

19:44Let's talk further . Next is , why are

19:46all these reactions inside this the

19:49same ones from aldehydes and ketones ? I

19:52am reminding you once . See the

19:53reactions first because they are needed

19:55right now . If you use HCN in NaCN ,

19:57basically , that's what was made , right ?

19:59HCN doesn't react directly . It has to

20:01be reacted with NaOH by making a buffer

20:03, like this . So , do you remember with

20:05aldehyde , if this is an aldehyde , then

20:07what does HCN do ? I told you about the

20:09plus-minus reaction . Its minus with its

20:11plus , and its plus with its minus . I

20:13have already told you about this

20:14reaction . So , it forms a cyanohydrin .

20:16This is cyanohydrin . Remember ? This is

20:18called cyanohydrin . So , this

20:20cyanohydrin that is formed of yours ,

20:23okay ? Cyanohydrin . So , the same

20:25reaction happened here that , brother ,

20:27if I am reacting glucose with HCN and

20:29NaCN , then what will I get ? My aldehyde

20:32will form a cyanohydrin . So , this is

20:34called gluco - from glucose , so

20:36gluco-cyanohydrin is what you have now .

20:39Okay ? Similarly , if you look at NH2OH .

20:44I have already had you do this reaction

20:45before as well . Hydroxylamine . Yes ,

20:47this is hydroxylamine . Do you remember

20:49this reaction with hydroxylamine ? It

20:51used to happen like this . Remove water

20:53from here . Huh ? And what did you get ?

20:55An oxime was formed . We are going to

20:57get an oxime . So , the same thing

20:59happened here that you took this

21:00carbohydrate . Inside this , what do you

21:02call it ? Reacted it with hydroxylamine .

21:04So , what did you get ? You got an oxime .

21:06So , what will we call this now ?

21:08Gluco-oxime . Similarly , if I talk about

21:11Lithium Aluminium Hydride . It is a

21:12strong reducing agent . It reduces

21:14aldehyde to form alcohol . So , what did

21:16we get here ? This group at the top , the

21:18aldehyde , what did it convert into ? It

21:20converted into your alcohol . Okay ? at 1

21:23° , this compound is called sorbitol or

21:27glucitol . Okay ? We have formed this . So

21:30the idea is that these three reactions

21:32confirm that we definitely have a

21:35carbonyl group somewhere . Okay ? If you

21:37look here , you have a carbonyl group .

21:39Carbonyl means a CO group . That is a

21:41separate matter . It is not confirmed

21:42yet . Whether it's a ketone or an

21:43aldehyde . We will look at that soon .

21:45But as of now , the presence of a

21:47carbonyl group is confirmed somewhere .

21:50Keep one thing in mind . When you are

21:52drawing these structures , this center

21:54here is also what ? It became chiral .

21:56Look closely , a chiral center is

21:58forming here . So , if someone asks how

22:00many chiral centers are in

22:01gluco-cyanohydrin ? Then there will be

22:02five . Because the one at the top has

22:04also become what ? It became sp3

22:05hybridized . Why wasn't it before , sir ?

22:07Wasn't it before ? Previously , it was

22:09sp2 , and sp2 hybridized is not a chiral

22:11center . An sp3 hybridized center is an

22:13option for a chiral center . Now let's

22:15move to the next . After this , if I talk

22:17about reaction with acetic anhydride .

22:20Now , how did we find out that we have a

22:22hydroxyl group inside it ? What has been

22:25confirmed so far ? Six carbons are in a

22:28straight chain , and one of them is an

22:30aldehyde or carbonyl . This much is

22:32confirmed . This was found out from the

22:34reaction when this was done with

22:35anhydride . This reaction has been

22:37performed . Here is a complete reminder

22:39that if you react alcohol with

22:40anhydride , you get this kind of

22:41compound . Acetylation happens in a way .

22:43I have done this two or three times .

22:45Yes . So this is your reaction . So how

22:47many such O will you have ? Just call

22:49them acetate groups . So , an acetate

22:51group has been added . How many will be

22:53formed ? They observed that when we

22:55carry out this reaction with glucose

22:57and anhydride , five moles of anhydride

23:00molecule are used . And what is formed ?

23:02Each one forms a penta-acetate there .

23:05Penta-acetate means the reaction is

23:07that you are removing hydrogen and

23:09adding this group . So you basically

23:11interchanged them here , look closely ,

23:12sorry , you are adding this group . Okay ?

23:15So now what ? You combined this with

23:17that . This group came in place of H. So

23:20now you have acetyl groups . How many

23:22are there ? On every alcohol . 1 2 3 4 5 ,

23:25so all five alcohols converted into

23:28acetyl groups . This proves that we have

23:31five alcoholic groups and all five of

23:33them are distinct . All right ? Did you

23:36understand this ? It is at one position ,

23:37and it is unstable anyway . So , we have

23:39obtained five separate hydroxyl groups .

23:41Next , let's react it with bromine water

23:43. It is a special oxidizing agent . What

23:45is its function ? Wherever it sees an

23:48aldehyde , it converts that aldehyde

23:50into an acid . If it sees an alcohol

23:53anywhere , it does not react with it . So

23:55, what happened in such cases ? Since it

23:57won't react with these , it won't react

23:59with the alcohol . It will only react

24:00with the aldehyde . So , by oxidizing the

24:02aldehyde , what did it do ? It converted

24:04it into an acid . It does not react with

24:06ketones . So they found out , because

24:08they had to check which carbonyl group

24:10it is , right ? Is it an aldehyde or a

24:11ketone ? So they observed that the

24:13carbonyl group is giving the aldehyde

24:16reaction , not the ketone one . Because

24:19of this , it proves that the carbonyl

24:20group is present as an aldehyde . So

24:23they confirmed the aldehyde reaction in

24:25this . So , as of now , what do we have ?

24:28Six carbons . One of them was a carbonyl

24:30, which turned out to be ? An aldehyde .

24:32So it is confirmed now . Six carbons

24:34with an aldehyde and we have five

24:36hydroxyl groups among them . This has

24:38been proven right now . All right ? Now

24:39let's move forward . Next is , now look

24:42at this , this is good . This is HNO3 ,

24:44now concentrated nitric acid is also a

24:47type of oxidizing agent . What does it

24:49do ? It will turn your aldehyde into an

24:52acid . It will also turn the 1 ° into

24:54an acid . But it does not react with 2

24:57° as it is . So what happens here ? Here

25:00, in this entire group of yours , this

25:02was two , this was two . The 2 ° and 2

25:04° will have no reaction with them .

25:06Nothing . But there will be a reaction

25:09with the aldehyde and with your alcohol

25:11. What will it convert into ? This into

25:13an acid , this also into an acid . This

25:15is called saccharic acid . And this

25:17saccharic acid gives the idea that you

25:19have , because we have to see if all

25:22five alcohol groups are the same , right

25:24? So they found out that out of those ,

25:27one alcohol , this alcohol below , is

25:29what ? This is of 1 ° , that is primary

25:31orientation . So , it means one alcohol

25:34is 1 ° . The rest of yours will

25:35generally remain here as ? They will be

25:372 ° . So , this is our confirmation as

25:40of now . Okay ? And let me show you one

25:42reaction . This is with phenylhydrazine .

25:44Okay ? A bit of an advanced reaction .

25:46Let's see what happens here . If I talk

25:48about phenylhydrazine , well , you guys

25:50have done this reaction before . If you

25:53remember , we did it like this . From

25:55here , I mean , like this is an aldehyde .

25:58Did I show it somewhere on the side ?

25:59No. This is an aldehyde or ketone ,

26:01whatever you have . Here comes NH2 . Okay

26:04? NHPH , so what used to happen ? It flew

26:07off from here , so it looked like this

26:09to us . Okay ? This will look like this .

26:12Double bond NNHPH . It looks like this ,

26:15you can see it . So , something like that

26:17happened here , just look closely .

26:19Carbon double bond NNHPH , carbon double

26:21bond NPH , so yeah , that's correct . Sir ,

26:24I understood this one . What happens

26:25over here ? The reaction with

26:27phenylhydrazine also occurs with this

26:30carbon . It also reacts with the second

26:31one . With both , and almost a similar

26:33thing is formed . Yes , look above and

26:35below , the same thing is forming . So ,

26:36it demonstrates this reaction here .

26:39This is called osazone . So , what does

26:41glucose do ? Glucose forms osazone .

26:43Which one ? When it reacts with

26:45phenylhydrazine . Here , three molecules

26:48of phenylhydrazine react . This is just

26:50theoretical information . That’s all .

26:53Moles of phenylhydrazine used are three

26:55moles . And it also proves the presence

26:57of the carbonyl carbon , which we have

26:59already covered before . There is no

27:01need for this reaction as is . It was

27:03just a reaction through which we can

27:05confirm that our carbonyl compound is

27:07present . Okay ? Now , look here . So ,

27:10these were all the reactions , sir . It

27:12gives so many reactions . But , there was

27:14a problem in this , and we need to sort

27:16that problem out . The problem that

27:20arose was that your glucose , if we talk

27:22in simple terms , should have given all

27:24the aldehyde and ketone reactions that

27:27we have studied so far . But there are

27:30some issues with it . Like , it doesn't

27:32give the sodium bisulfite test . It

27:35doesn't give your Schiff's test . It

27:37doesn't give the 2,4 - DNP test . Its

27:39penta-acetate doesn't give the

27:41hydroxylamine test . So , it should have

27:44given all these tests . If it has

27:46glucose , sorry , if it has a carbonyl

27:48group , if it has an aldehyde group ,

27:50then we are going to expect some

27:52reactions . It was expected that , man ,

27:54it should have given this reaction . But

27:57it is unable to give this reaction . And

27:58if it is unable to give this reaction ,

28:00then you have a very big concern : why

28:02were these reactions not found ? So when

28:05scientists saw that some reactions were

28:07happening inside it but some were not .

28:09Then they analyzed this structure in

28:11more detail . Only then was it

28:12discovered that the glucose we thought

28:15was in open form , glucose is not open

28:17at all . Glucose is actually closed .

28:20Meaning , it has a cyclic structure . So

28:22that is what is written . Above points

28:24can be explained by assuming cyclic

28:25structure of glucose . Now , how does

28:27this cyclic structure come about ? We

28:29have to create this . Questions have

28:30been asked on this . So understand its

28:32technique . Look , guys . This is glucose

28:34we have . Call this number one . Call

28:36this number two . Call this three . Call

28:38this four . Call this five , call this

28:40six . So the one coming at number five ,

28:43this oxygen , we have seen the reaction

28:46of this oxygen with the aldehyde ketone

28:49. When we have , what do you call it ?

28:51Alcohol , this is the alcohol group . We

28:53have seen the reaction of alcohol with

28:54aldehyde ketone . Remember ? Acetal ,

28:56hemiacetal , ketal , we have to do the

28:57same thing here . So what will happen

28:59here ? It attacks this , man , and tries

29:02to open it up . Okay ? And then there is

29:04that same hydroxyl . So you could also

29:06do it by adding and subtracting , it's

29:07your choice . So this attacks and the

29:09oxygen forms like this here . So it

29:11starts to form a cyclic compound . Now

29:13what does this form from glucose ?

29:15Something called a pyranose structure .

29:17The thing drawn below is pyran . So it

29:19will be something like that , right ?

29:21It's six-membered and oxygen is in the

29:22ring . So that is why it is called

29:24pyranose , that a six-membered ring is

29:26formed in which there is one oxygen .

29:28Okay ? Now one more thing . Because this

29:31aldehyde of yours is what ? This is

29:34planar . Planar means 120 ° , you have

29:37the whole plane . Just like a plane ,

29:39exactly . Okay ? Like , suppose this is a

29:41plane I have . Okay ? This is a plane . If

29:43it is planar , if it is a structure like

29:44this , then the attack could have

29:46happened from this side , from the back

29:47side , or from the front side . So , if

29:49there is a possibility of an attack

29:51from both sides , then we have to

29:54understand that after the attack , this

29:56OH molecule can go either to the right

29:59or to the left . Now , two possibilities

30:01arise : whether it goes to the left or

30:03the right . So , we have to understand

30:05where it will go . Okay ? So , that is why

30:07a structure has been formed there . I am

30:09bringing those same structures here .

30:10Look closely . These structures are

30:11appearing here . Okay ? That is , you had

30:14this structure . It has been linked here

30:16. Okay ? It is linked here like this . I

30:18will show the linking like this . It is

30:20linked this way . It is linked like this

30:22. Okay ? They haven't drawn this one . It

30:24is linked in its entirety like this . So

30:25, after this linking , will your carbon

30:28that was at C1 go to the left or to the

30:31right ? The structure depends on that .

30:32Now , look , I think it is clear up to

30:35this point . You have to create the

30:36structure from here . Understand the

30:38technique for that . Any group that is

30:40on the left side , we take it as above .

30:42Meaning , in this structure , the left

30:44ones are above and the right ones are

30:46below . For example , let's look . Let's

30:48talk about this . So , the OH group on

30:50the second position here , where is it ,

30:52sir ? This is on our right side . Right

30:54side means below . So , what will this be

30:56? Below . Similarly , look at this group .

30:58Focus on this . On which side is it ? It

31:01is on the left side . Left side means

31:03above . So , the OH of its third carbon ,

31:05where did it go ? It went above .

31:06Similarly , look at number four ; right

31:08means it will be below . Okay ? I think

31:10there is no problem with this . 2 , 3 , 4

31:12— I think everything is sorted here .

31:15The problem is with five . On number

31:17five , you have a CH2OH group attached ,

31:19along with an H. So what to do ? Look at

31:22this simple rule . For the C5 carbon ,

31:24whatever is the outer part comes to the

31:26top . That is the rule ; whichever has

31:29more mass , here there is a CH2OH group .

31:32And one H. Which one has more mass , sir

31:34? This one has more mass . Okay ? This

31:36has more mass . And if its mass is

31:38higher , okay ? Whichever has more mass ,

31:40what will we say ? It will come towards

31:43the top . So , this group will remain

31:44towards the top . Look at both

31:45structures , it remains at the top .

31:47There is no issue with this . Now let's

31:49come to the C1 position . This is where

31:51the alpha-beta difference is created .

31:53Now it could have been on the right

31:55side . Like , look at this . Could be ,

31:57which side is it on here ? Sir , this is

31:58on the right side . Right means what for

32:00us ? Right means below . So this came to

32:02your below position . This is on the

32:04left side . This came to your above

32:06position . If it comes to your below

32:08position . You have to look at the C1

32:09carbon . This is the C1 carbon . If OH is

32:11below on the C1 carbon , it is called

32:14the alpha form . If it is above on the

32:16C1 carbon , it is called the beta form .

32:18So this is alpha-D-glucopyranose . This

32:20is beta-D-glucopyranose . Questions

32:23asking to draw its structure have

32:25appeared in many PYQs . So you should

32:27know how to draw this structure . Sir ,

32:30if I try to draw this structure after

32:31all this drama , I will go crazy . I am

32:34already troubled by Physics . I know . So

32:36there is a technique for it , let's

32:37understand that . What is the technique ?

32:39Just understand the cyclic structure

32:41and the trick for glucose . That is ' Ji

32:42Baba ' . Okay ? The question will be given

32:44directly . Right , draw the structure of

32:47beta-D-glucopyranose . Don't fail . So

32:50remember the technique for

32:51beta-D-glucopyranose . Baba , Baba Ji ,

32:53Baba Ji . A song is also trending these

32:56days , right ? One is that Baba Ji , the

32:58IIT ones are going around . Second ,

33:01what's that name ? Not Baba , ' Baba Ji

33:03Sadi Hi Marti ' , some song like that ,

33:05right ? It has a very different trend

33:07going on as well . So remember Baba Ji ,

33:10' Ji ' . Now Baba Ji , yes , the song

33:13started playing in my head , it happens .

33:17So what is Baba Ji saying , listen . Baba

33:19Ji is saying 4 2 3 1 , meaning your

33:21number four carbon , that is below . So

33:24that means understand here , okay ? Look

33:26at this , let me make it with this ;

33:28carbon number four is below , okay ?

33:30Carbon number three is above , okay .

33:33Then carbon number two is below . Then

33:35carbon number one is ... one . This is

33:37done . And everyone knows about C5 . It

33:39contains CH2OH which stays above . The

33:41rest , your H stays below . These are

33:43made . So this H , this H , this H , this H

33:45, this is my beta-D-glucopyranose

33:47formed . Huh ? Take a look at this . Any

33:49pain or trouble ? Look here , brother . It

33:51is just like this . Look at beta below ,

33:52take a look . Below , above , below , above

33:54. It is just like this . Below , above ,

33:56below , above . Yes . Now the point is ,

33:58what is the technique if you want to

34:00create Alpha D ? Let me make Beta . Okay ?

34:02What is the difference between Alpha

34:03and Beta , sir ? It is the C1 difference .

34:04Just flip C1 . So , looking at this ,

34:06let's make C1 . Just look at this whole

34:08thing . This is formed , sir . This is

34:10formed , sir . Okay ? This is formed , sir .

34:12There is no trouble up to here . There

34:14is no trouble up to here . Now , this

34:15needs to be flipped . C1 gets flipped .

34:17So , if you want to go from Beta to

34:19Alpha . Change C1 , just make this much

34:21change . Change C1 . Okay ? How much will

34:24it become , brother ? Here the OH will

34:26come down and the H will come up ,

34:28brother . This is the structure . Use

34:30this technique to draw this structure .

34:32Your game is set . Let's understand a

34:35couple of terms here which are actually

34:37part of your optical isomers . But let's

34:39understand it . Okay ? What do they call

34:41them ? What are epimers ? I mentioned

34:44diastereomers inside that .

34:45Diastereomers having different

34:47configuration across one center . What

34:49does that mean ? In these two ,

34:51everything is the same except at one

34:53center . In this group , your OH is on

34:55the right side . In this , H is on the

34:58left . In this group , your OH is on the

35:00left . H is on the right , meaning one

35:01change has occurred . Yes , one change .

35:04If there is one change in your life .

35:06Okay ? One change happens . What do we

35:09call such guys ? They are called epimers

35:11. So , like glucose and mannose are what

35:14? They are epimers of each other . Just

35:16one change should be there . Okay ? Now ,

35:19if these epimers of yours are in cyclic

35:22form , then cyclic epimers are basically

35:24given a special name . They are called

35:28anomers . So , here if you look , they can

35:30be in open form too . Epimers are , you

35:32see , a large category . So , a large

35:33category means they can be open or they

35:35can be closed . Those which are closed ,

35:37the cyclic ones , are called anomers . So

35:39, like we have Alpha-D-glucose and

35:40Beta-D , it was the same in that too .

35:42Yes sir , there were changes at C1 .

35:43Everything else remained the same . So ,

35:45cyclic epimers are termed as anomers .

35:47So , which is the bigger category ?

35:48Epimers . So , are all anomers epimers ?

35:51Oh sir , absolutely they are . Are all

35:53epimers anomers ? No sir . The open ones

35:56are epimers but not anomers . Done , is

35:59the concept understood ? Yes sir . Next

36:02is , if I talk about mutarotation . So

36:04look , mutarotation is a very simple

36:06concept . These three brothers , all

36:09three are brothers . Alright ? The

36:12alpha-D glucose that you have , as I

36:14said , it exists in two forms . If you

36:16take glucose , it exists in both

36:18alpha-D-glucopyranose and

36:20beta-D-glucopyranose . And they form an

36:22equilibrium . Sir , if I do this and just

36:25take alpha-D , brother ? You take it and

36:27give it some time . It starts converting

36:30back into this one and that one . So an

36:32equilibrium is established . Yes , there

36:34are some conditions for this

36:35equilibrium . You have to provide water ,

36:37etc. Amphiprotic solvents usually work

36:38faster . But yes , what happens is that

36:40these three want to stay together .

36:42Otherwise , they get moody without each

36:44other . Alright ? They cannot live alone .

36:46So , because these three establish an

36:49equilibrium with each other . So ,

36:51whenever you catch them . Alright ?

36:53Whenever you catch these three , I have

36:55already given you the angles . Like , its

36:57angle is 112 ° , and that one's is 18.7

36:59° . So if you keep them together , their

37:01average angle comes out . That average

37:03angle is how much ? 52.7 So you started

37:07at 112 , you came back to this . You

37:10started at 18 , you got up and came back

37:12to this . You started with glucose , then

37:14came back to this . So in the end , what

37:16is the value always ? It remains fixed .

37:18That fixed value is this . And we call

37:20this concept mutarotation . That you can

37:23start the angle with this alpha one .

37:25But you will eventually reach 52.7

37:27again . So this point is written here .

37:29If alpha-D-glucopyranose is dissolved

37:31in aqueous solution , the optical

37:32rotation changes and comes to this .

37:34Whether you take beta-D-glucopyranose ,

37:36it will also come to 52.7 . The concept

37:39is called mutarotation . These are some

37:42of your basic terms . I hope that is

37:44clear . I am telling you one or two

37:46extra points as well . Alright ?

37:48According to this , so that because some

37:50students from state boards were also

37:52asking . Sir , this comes there , that

37:53comes there . Alright ? I have covered

37:56most of the things different from CBSE

37:58as well , so that you , the state board

38:00students , also benefit . Alright ? Yes ,

38:03look , it does not mean that 100 % of

38:05everything will be covered according to

38:06all boards because there are small

38:08changes in every board . And we have to

38:10make the video very , very crisp . I have

38:12always said that making short videos is

38:13the toughest task . Because there is a

38:16lot of content and you have to present

38:18all that content in a crisp way . So it

38:20is possible because our target was

38:22initially CBSE . There is a projection

38:24that we have to proceed according to

38:26the CBSE boards . Yes , according to that

38:27, I am mentioning a few extra things so

38:29that your CBSE portion is fully covered

38:31and some other state boards also

38:33benefit . Okay ? And still , if any of you

38:35, because I saw that I even mentioned

38:37in the previous video , that brother ,

38:39vectors are not in the test for CBSE .

38:41Still they say , " Sir , no , we want to do

38:42it . " So man , just search my video with

38:45the chapter name . You will find it

38:46there . It is just one topic you have to

38:48look at . You will find it . Okay ? So

38:49please , there is a thing called

38:52absolute spoon-feeding . Okay ? Like , "

38:54Sir , you do this too . " Someone says , "

38:56Do this also . " " Do this also . " " Do this

38:58also . " " Do this also . " Should I do

39:00everything ? Should I take the exam for

39:02you too ? Brother , try to have that

39:04temperament that , " Yes , we will do it . "

39:07You have provided us this too . You have

39:09provided us this too . You have provided

39:10so much . We have done everything . Now

39:12the rest is your hard work . And from

39:15this same batch , there will be kids who

39:17will score full marks in this . And in

39:19this same batch , that is a very bad

39:21thing to accept . But in this same batch

39:24, there will also be kids who , what

39:26should I say , won't get such good marks

39:28. So where is the difference ? Am I

39:29going to their homes separately to

39:31teach those who are scoring 70 out of

39:3370 ? No. The difference is that this kid

39:36who scored 70 has worked very hard on

39:38themselves after this lecture . And it

39:41is true for everything . The teachers

39:43are the same . The teachers are all

39:44similar , I mean whichever teachers you

39:46are studying from . Are they teaching

39:47everyone one by one ? They are teaching

39:49everyone the same . So why do some get

39:50good results ? Some get bad results . You

39:52need to look within yourself for that .

39:54Understand that . Okay ? Grow up a little

39:57, become a little more mature .

39:58Everything has been given to you . Now

40:00you have to study . Huh ? And if you are

40:03only thinking like this . Sir , I watched

40:05your video . The rest will be seen later

40:07. Oh man , you have to revise after that

40:09. Question practice happens . A thousand

40:11things need to be done . If you think

40:13that just by watching lectures

40:15everything will be done . No , the hard

40:17work after lectures shows the reality ,

40:20and that will decide how much you can

40:22achieve . Okay ? Now let's come to the

40:24summary . That is alpha-D-glucopyranose

40:29and beta-D-glucopyranose , the

40:31hemiacetal forms , because you see , this

40:35OROH and the aldehyde part here , it

40:38converts into a hemiacetal . Okay ?

40:42Glucose is glucose , you see . If it

40:45reacts , it converts , so glucose is

40:46generated , and we need the glucose

40:48group in beta-D-glucopyranose . Look ,

40:50there is a hemiacetal in this , so it

40:52can convert into glucose . And I already

40:54told you one thing :

40:55alpha-D-glucopyranose and

40:56beta-D-glucopyranose have a superpower .

40:58They can convert back into their

41:00glucose form . So , effectively , if I say

41:02, do you see an aldehyde in

41:04alpha-D-glucopyranose ? Oh yes , it will

41:06show up once it converts . Yes . That is

41:08exactly why mutarotation happens in

41:10that conversion . So , what are these two

41:12? They can generate hemiacetal forms .

41:13They will pass Tollens ' and Fehling's

41:15reducing tests because there was an

41:17aldehyde in it , so that makes sense .

41:19And these two guys can convert into

41:21them . Okay ? So , that's done . And the

41:24number of chiral centers . This will be

41:25a different point because the chiral

41:27centers in this are here . Here , here .

41:29This is it . These are the four chiral

41:30centers . But in this one , there will be

41:32five . So here , here , here , here , and

41:34here . Okay ? We have five chiral centers

41:37in this one . Okay ? Similarly , there

41:39will be five in beta-D-glucopyranose as

41:40well . So there is a difference in

41:42chiral centers . Otherwise , everything

41:43else will remain similar in both . Now

41:45let's come to the next , which is

41:46fructose . Now , if you have understood

41:48this , brother . Okay ? If your glucose

41:51matter is clear , the glucose part . Then

41:53fructose has some similar behaviors .

41:55The only difference is . Glucose has an

41:58aldehyde . Fructose has a ketone .

42:00Otherwise , at a broad level , everything

42:02is . Similar . So what is going to happen

42:04here ? Fructose has arrived . So in

42:06fructose , the entire chain is here .

42:09Take a look . So this is the chain . It

42:11has a ketone at the second position .

42:12What about everything else ? Similar . So

42:15, ketone is at the second number . If

42:17you look at the rest , the structure

42:18looks almost similar . Okay ? You have to

42:20do the same thing here . Nothing has

42:22changed . This number five one you have ,

42:24it used to go to the aldehyde . This

42:26will go to the ketone . So it will go to

42:28the second number . It will open up like

42:29this . So how many membered chain will

42:30be formed ? Look here for a second . A

42:32five-membered chain is formed here .

42:33This is a five-membered cyclic oxygen

42:35chain being formed . This is called

42:36furan . So this is called the furanose

42:38structure . As it is , all properties are

42:40similar . There is nothing new . The

42:42things we discussed for glucose , do the

42:43same for fructose , so two forms will be

42:45made . Alpha D-fructo , Beta D-fructo .

42:47When we make them here . I have made

42:49this . The slides are the same from here

42:51. So in Alpha D-fructo , what will you

42:53have ? That group , this OH group will be

42:55at the bottom . In Beta D-fructo , your

42:57OH group will be at the top at the C1

42:59position . So if you check , friends , the

43:01rules are the same , I am not saying

43:02anything has changed . Look , on the

43:04fifth carbon it is up , this fifth

43:06carbon is up , we already knew that . Sir

43:08, OH is down at C1 , so it will be alpha

43:11. At C1 ... here it is the C2 position ,

43:13because the aldehyde comes at the C2

43:16position , so you basically have to look

43:18at C2 . So , if OH is coming down at the

43:20C2 position , it is alpha . If OH has

43:23come up at the C2 position , we will

43:25call it beta . Only that much happened .

43:27These are the same alpha rules , all of

43:29them . C5 was also mentioned . What about

43:31three and four , sir ? On three and four ,

43:33you will look at it like this . On three

43:35and four , if it is on the left side ,

43:36then look , at three it is on the left ,

43:38so it will appear at the top . And if at

43:40four it is on the right side , it will

43:42appear at the bottom . So all those

43:44rules we did in glucose , you have

43:46covered all those things . In this , it

43:48is only and only a game of the aldehyde

43:50. What was an aldehyde there is a

43:52ketone here . There it used to be the C1

43:53carbon . Here it will be the C2 carbon .

43:55Everything else is same . Now look , the

43:57summary is also the same , alpha .

43:59D-fructofuranose , this will also be in

44:01equilibrium with fructose ; it will be

44:02in equilibrium with Beta D-fructose , so

44:04Alpha , Beta , and Fructose remain in

44:06equilibrium with each other . Again ,

44:08mutarotation is also exhibited by

44:10fructose . Alpha and beta are anomers ,

44:12you told us this too , sir . And what

44:15will be the number of chiral centers ?

44:17In the open chain , there are three

44:18chiral centers ; in the closed chain ,

44:20one more chiral center is generated , so

44:21four here and four there . So , that is

44:24about your fructose , and both

44:26carbohydrates are clear now . That is

44:28glucose and fructose . Now , let's move

44:31on to the disaccharides . So , we have

44:34finished all the monosaccharides . Now ,

44:36we will talk about disaccharides . Just

44:38a ... yes , this is done . Now look , in

44:41disaccharides , if I see , I have sucrose

44:44, maltose , and lactose ; these three .

44:46Now we have to look at the structures

44:48of all three . Okay ? In all three , we

44:50must know which ones — because ' di '

44:52means they are made of two units . So ,

44:54which two units are they , and what is

44:56their linkage ? That is what matters .

44:58These are two very important questions .

44:59And if you know this , you will be able

45:00to draw the structure yourself . Okay ?

45:02For instance , let me first talk about

45:04sucrose . So , what do you have ? You have

45:06to take glucose , which one ? Alpha D. So

45:08, you have to take alpha-D-glucose . So ,

45:10this is alpha-D-glucose and

45:12beta-D-fructose . You will be able to

45:14draw these , alpha ... alpha . Alpha

45:15glucose and beta fructose . Now , all the

45:17structures have been explained to you .

45:18You have to draw them . So , sir , we have

45:20drawn both of them . You have drawn

45:22these . Now what does it say ? It says C1

45:24- C2 glycosidic linkage . Now , how is the

45:27glycosidic linkage formed ? Watch this .

45:29You have glucose . This is the numbering

45:32. 1 , 2 , 3 , 4 , 5 , 6 ; do the numbering

45:35for this one as well . 1 , 2 , 3 , 4 , 5 , 6 ,

45:40so C1 - C2 . C1 of what ? Its C1 and the C2

45:44of beta . So , this is C1 and this is its

45:47C2 ; the OH groups they have — so this

45:49is the OH group and this is the OH

45:51group . From these two , what you have to

45:54do is ... Subtract OH — subtract water .

45:56So , what did you do ? You removed water

45:59from here like this . So , if you remove

46:02water from OH and OH , what will be left

46:03? Only oxygen will remain . Yes . So ,

46:05this group we have is called a

46:07glycosidic linkage . So , this linkage

46:09that is formed , this is the glycosidic

46:11linkage that is being referred to . Now ,

46:14you have already been told one thing

46:16during the structures , or I will tell

46:18you again . In glucose , it's C1 , and in

46:22fructose , it's C2 . So C1 of glucose and

46:26C2 of fructose are their main points .

46:28Because the aldehyde forms at C1 . The

46:30ketone forms at C2 . So , man , these two

46:33are deciding everything . The decision

46:35is coming from them one way or another .

46:37If these two are deciding everything ,

46:40the point is that C1 and C2 positions

46:42must be free . Now , those with free C1

46:45and C2 positions can be called reducing

46:47. They will exhibit all those reactions

46:49. Those without them being free have no

46:51options . Like here , its C1 is not free ,

46:54so it is blocked . Its C2 is not free .

46:57Its C2 is blocked . So you had to keep

46:59the C1 and C2 positions free . Now , both

47:01are blocked here . So will this be

47:04reducing ? Is this a reducing sugar ? No.

47:06So it is not a reducing sugar . It

47:08cannot generate a hemiacetal in this

47:09case . The generation was supposed to

47:11happen from here . It is unable to

47:12generate it . So it won't be able to

47:15show Tollens , Fehling , Benedict , or

47:17mutarotation . It is a straightforward

47:20game . Because everything is decided by

47:22its C1 and its C2 position . If you

47:25block those , then it becomes a mess . I

47:27hope that is clear to everyone . Alright

47:29? There is also a trivial effect .

47:31Regarding sweetness , fructose is the

47:33sweetest . Then comes sucrose . Then

47:34glucose . So if you want a lot of

47:37sweetness , you can add fructose there .

47:39Let's talk further . The next one is

47:41regarding maltose . The arrangement of

47:44maltose is alpha-D-glucose and

47:46alpha-D-glucose . Meaning you have to

47:48take both alpha-glucoses . Now , where do

47:50you link the alpha-glucoses you've

47:52taken ? It is a C1 - C4 linkage . So from

47:55its C1 , look here , connect its C1 to

47:58its C4 . So this C1 and this C4 , what

48:01will you do from here ? You will remove

48:02water from here . So you have removed

48:04the water . A glycosidic linkage is

48:05formed . This is your maltose . If you

48:08look inside this maltose , one position

48:11of the alpha-glucose is ... Free . Look ,

48:15the alcohol of the C1 is free . If this

48:17becomes free . Then man , it will do all

48:19the reactions . Huh ? The hemiacetal is

48:21also free here . The hemiacetal is free .

48:23So all those tests will start ...

48:25Becoming available here . Is the matter

48:28clear to you ? Huh ? Yes or no ? Yes .

48:31Let's move forward . Next is , if I talk

48:33about gluco ... Yes . I am telling you a

48:35small thing right now . It is used in

48:37the next one . Glucose plus Galactose .

48:40If you look , everything is similar in

48:43glucose and galactose . The difference

48:45is only at the C4 position . So C4 is

48:47the one that is going to change . Just

48:49one second , buddy . Yes , brother . Now

48:54let's talk about glucose here . So , for

48:56glucose's C4 and if you look at its

48:58galactose , what is at the C4 position ?

49:01There is a kind of change in them . So

49:02the configuration is different . So it's

49:04an epimer ; we call them C4 epimers .

49:06It's the same deal . What should you do ?

49:08If you got this form , right ? Did you

49:11understand the change between glucose

49:13and galactose ? Now , in the same way ,

49:15suppose I want to make

49:16beta-D-glucopyranose and let's say I

49:18want to make beta-D-galactopyranose ,

49:19then I taught you to make

49:20beta-D-glucopyranose earlier ; just

49:22change its C4 . So , look , you

49:24interchanged the C4 position , so what

49:26did it become ? It became

49:27beta-D-galactopyranose . Now we have to

49:29pick this up . This is the one that we

49:31have to take out . What to do with this ?

49:33If you look here , if you take

49:35beta-D-galactose and beta-D-glucose and

49:38connect them with C1 - C4 , then this is

49:41beta-D-galactose . This is

49:43beta-D-glucose . C1 - C4 , so look at its

49:46C1 , you have to connect C1 to C4 . So

49:50this C1 and its C4 , so from here it

49:52will ... It will connect from here .

49:53Remove water from here . Remove water

49:55from here , from here . When you removed

49:57water , a glycosidic linkage was formed .

49:58Now look , even now its C1 is still free

50:01. And if C1 is free , if this is free ,

50:04then a hemiacetal can form . And if sir ,

50:07a hemiacetal is formed , then all these

50:09things of ours will ... will be

50:10successful here . Yes . So what is this ?

50:13This is lactose and this is a naturally

50:16occurring sugar found in milk . So this

50:19is the one that is your final

50:21disaccharide that we have to do . There

50:24is no need to worry about depth in

50:26these disaccharides . You should know

50:28what it is made of . And if you follow

50:30the way I am telling you , you won't

50:32have to memorize the structures . Okay ?

50:34If you go step-by-step , it is very ,

50:36very okay , meaning it is simple in the

50:37sense that you just have to remember

50:39this . I will have you make a table for

50:40this at the end . Okay ? And let's see .

50:43Let's talk further about

50:43polysaccharides . We have to look at

50:45three polysaccharides . One is cellulose

50:47, one is starch , one is glycogen . Okay ?

50:49Glycogen . Let's look at this . Let's

50:51talk about cellulose first . I already

50:53told you that if you put cellulose in

50:55water , it's a polysaccharide made of

50:57glucose units . From what ? Which unit is

50:59formed ? Beta-D-glucopyranose units are

51:02formed . How are they linked ? They are

51:04linked C1 to C4 . So if you see , here

51:07you have beta-D-glucopyranose . Its C1 ,

51:10so the C1 of one and the C4 of the next

51:13, this is its C4 . So this is one and

51:15this was four . So you will link from

51:18here . It will link from here . Similarly

51:20, it will link from here . And this is

51:22how it will link from here , whichever

51:23one comes here . Similarly , it will link

51:25to some previous one . So as these keep

51:27linking , you will see your structure

51:29being formed like this . Now , this

51:31structure that is being formed , we will

51:33call it cellulose . Is this clear to you

51:36guys ? Again , the same thing , in glucose

51:38, what did you have to do with the C1

51:39unit ? You had to keep it free . But

51:41everyone's unit got stuck somewhere or

51:43the other . Huh ? It will get stuck with

51:45someone or the other . So , because it is

51:47getting stuck with someone or the other

51:48. It is not staying free . It is not

51:50staying free . So all these properties

51:51will do what ? They will fail here . So

51:53this is going to fail . So it is written

51:55. Well , one more thing , since hydroxyl

51:58groups are near to each other , hence

52:00intramolecular hydrogen bonding is

52:02possible , because you have what is

52:04called , do you understand

52:05intra-molecular , inter-molecular ? What

52:08is being said here is that the hydroxyl

52:10groups are close to each other , so all

52:11these hydroxyl groups are very close to

52:13each other , so what starts happening

52:14between them ? Intra-molecular starts

52:17happening between them and you guys

52:18have understood by now that where there

52:20is intra-molecular hydrogen bonding ,

52:22intra means everything happens within

52:23your own school , so there is no need to

52:25go outside . Right ? So where

52:28intra-molecular happens , there is no

52:30scope for inter-molecular after that .

52:31And if there is no scope for inter ,

52:33then it is water-insoluble . This point

52:35is important . That is why this

52:37cellulose , you know , you know , have you

52:39ever ... It remains in the cell wall ,

52:41etc. So it is not that it is

52:43water-soluble . Why ? For water

52:45solubility , you need to perform

52:47intermolecular hydrogen bonding . Next

52:49is starch . What do you get when you put

52:52starch in water ? You get the

52:54alpha-D-glucopyranose alpha form . Now ,

52:56to understand starch , it has two parts .

52:5915 to 20 % is what we call amylose , and

53:01the remaining 80 to 85 % is called

53:04amylopectin . There is a slight

53:05difference in the structure of both .

53:06Let’s take a look at both once . If I

53:08talk about amylose first . It is an

53:10extension of the maltose unit . You have

53:13remembered the maltose structure . The

53:14C1 - C4 connection in it , right ? So , you

53:17just have to continue that C1 - C4

53:20connection as it is . Extension means

53:22just keep continuing the same . So , make

53:24maltose . Make two maltose units , just

53:26keep continuing forward . Just recall it

53:27. It used to connect from here like

53:28this in between . Okay ? It was connected

53:30from here like this . It was connected

53:31like this . This was fully connected . So

53:33, C1 - C4 alpha glycosidic linkage . You

53:35have to keep continuing like this . Keep

53:36doing it , keep doing it . I hope this is

53:38clear to everyone . Yes . So , water

53:40soluble due to the availability of free

53:42hydroxyl groups which can form

53:44intermolecular hydrogen bonding . Now ,

53:46these groups here , these ones , they do

53:48your intermolecular hydrogen bonding .

53:50Okay ? They are relatively free , so they

53:53can go for intermolecular hydrogen

53:55bonding . They are not very close

53:56together in this . There is an option

53:58for the side groups . Okay ? And on top

54:00of that , there is no branching . When

54:02branching starts to happen , then it

54:03creates a problem . So , I think it is

54:05clear to you guys that there is no

54:06scope for branching here . Yes , because

54:08your C1 is trapped , and you only have

54:10to look at the C1 of glucose . So , we

54:12would not expect these things anyway .

54:14Okay ? Our expectation for it ended

54:17because our C1 is gone . But yes , it is

54:19water soluble because of intermolecular

54:21hydrogen bonding . Let's talk about

54:23amylopectin . Amylopectin is a slightly

54:25more complicated matter . In the sense

54:28that we had this C1 - C4 alpha glycosidic

54:30linkage coming along . The C1 - C4 linkage

54:33was coming . This is correct . There is

54:35C1 - C6 alpha glycosidic branching . What

54:38does that mean ? If you look at the

54:40structure , this was your C1 . This is C1

54:43, this is C1 . This is your C6 . Its C6 ,

54:47this C6 was this carbon . What comes

54:49between them ? Glycosidic branching

54:51happens from here . So , take a look at

54:52the glycosidic branching . The branching

54:54starts from here . Yes . And because of

54:57this branching occurring here , it

54:59starts to branch a little . In the sense

55:02, this is one layer . This is the second

55:04layer . Branches start forming between

55:05them like this . So when does this

55:07happen ? After every 25 to 30 units .

55:09After every 25 to 30 units , what

55:12happens here ? It starts branching . So

55:14these structures don't remain free .

55:16Meaning , if I talk about amylose , it

55:18was going straight like this . Yes . But

55:21what is happening now ? In pectin ,

55:22layering starts occurring like this .

55:23Branching starts occurring . Because of

55:25that , the hydrogen bonding is affected .

55:26Yes . Because hydrogen bonding needs

55:28some space . If branched layers start

55:30forming , then there is no space left .

55:32So these points are written here . That

55:34is , the structure is like this . C1 - C4

55:35gone , C1 - C6 linkage . C1 - C4 gone . C1 - C6

55:38linkage continues like this . So when

55:41branching takes place , intra-molecular

55:43hydrogen bonding becomes more feasible .

55:44Hence , amylopectin is water insoluble .

55:47Because what will happen between them ?

55:48Now , these structures are shown here

55:51better . But that's okay ? I'll show it

55:53like this . This structure will bond

55:54with this one . Like this , the incoming

55:56water will bond with it . This is how

55:58your hydrogen bonding occurs . It starts

56:00to become intra-molecular . It will

56:01involve inter-molecular too . The next

56:03is your amylopectin , which I told you

56:05about . Okay ? Now yes , I think you have

56:08understood this thing . C1 is just left

56:10over . So all these things will fail .

56:13And then I will tell you the difference

56:16between them . 15 to 20 % of your starch

56:18is this part . That is 80 to 85 % . This

56:21is linear . That is branched . This is

56:24water soluble due to intermolecular

56:25hydrogen bonding . That is water

56:27insoluble due to intra-molecular

56:29hydrogen bonding . C1 - C4 alpha

56:31glycosidic linkage is its structure . I

56:33have explained these structures

56:34completely . This is non-reducing . That

56:36is non-reducing . If a question comes

56:38like finding the difference between

56:40amylose and amylopectin . Then I have

56:42given you all the points for a

56:43four-mark question . Okay ? Next is

56:46glycogen . Now if you look at glycogen ,

56:49it has a similar structure to

56:51amylopectin but the frequency of

56:53branching is higher . You just saw

56:55amylopectin . This was amylopectin .

56:57Everything is the same . Where the

56:59branching was happening after 25 units ,

57:01just reduce the branching there . Look

57:03closely . How much should I do ? After 10

57:05units . So if branching happens after 10

57:06units , everything else is the same . So

57:07it is not different from glycogen . Just

57:09reduce the branching of amylopectin and

57:11you will get glycogen . So I think this

57:13structure is simple . So we don't have

57:14any load regarding this . Now comes the

57:16summary of this whole thing , and here

57:18is your table . If you memorize this

57:20entire table , your maximum

57:22structure-based questions will come

57:24from here . Whether I am talking about

57:27disaccharides or I am talking about

57:29polysaccharides . Most of the things

57:31will be covered within this . This is

57:34your complete summary . I have written

57:37its units here . I have written their

57:39linkages here . Whether it gives a test

57:40or not , all of that is written here .

57:42This is the entire summary of what I

57:44taught for the last hour . I would

57:46suggest you stick it in front of you .

57:48Because it will definitely take some

57:50time to memorize . Okay ? As I said at

57:52the beginning of the chapter , the

57:54chapter is a bit theoretical . The

57:55topics are such that you will have to

57:58write , revise , and look at them

58:00repeatedly . There is no arguing about

58:01it . Sir , will it happen this way or

58:03that way ? No ; you have to do it . It

58:05takes effort , you have to memorize , it

58:07is theoretical , you have to study ,

58:09there is no other option . Okay ? Sir ,

58:11why is it like this ? Sir , why is it

58:12like that ? Brother , it is what it is .

58:15Okay ? Now you have to score marks and

58:17do not leave this topic . So there are a

58:20few pages , the same questions are being

58:23repeated again and again . Theoretical

58:25questions come , so why do you want to

58:27leave such a topic , man ? Okay , just go

58:29through it . Alright , let's move on .

58:31Next is DL configuration . Look here ,

58:33like this is glyceraldehyde . What you

58:36have to do is ? You have to , like ,

58:37consider this Carbon 1 , this Carbon 2 ,

58:40and this Carbon 3 . This is the last

58:42carbon , so this is the second to last

58:43carbon . Similarly , Carbon 1 , Carbon 2 ,

58:46Carbon 3 . This is the last carbon , this

58:47is the second to last carbon . On the

58:49second to last carbon , the OH group is

58:51on your right side . This is the right

58:54side . Okay ? In the same way , the OH

58:56group on the second to last carbon is

58:57on your left side . Yes . If it is on the

59:00left side , then it is called the L-form

59:02. It is capital L. If it is on the

59:04right side , it is called the D-form .

59:06This is capital D. The D and L we are

59:10doing right now . The small d and l that

59:13you did earlier in the racemic mixture

59:15have nothing to do with this . There is

59:18no connection at all . So , the D / L

59:19configuration is just a configuration

59:21that specifically arranges these

59:23molecules . You have to look at the

59:24second-to-last molecule . If it is on

59:26the left side , it is L ; if it is on the

59:28right , it is D. Now , why did we do this

59:30? Because if you look at glyceraldehyde

59:32, actually , if we start from three ,

59:34then from three to four , four to five ,

59:36five to six , in this way you can build

59:37up the molecules . How that is tested is

59:40not in our syllabus , but you can step

59:42up the series . But yes , there is one

59:44point : if you start with the D-form ,

59:46then you have to make all D. If you

59:48start with the L-form , then all L are

59:50formed . Like if I have to make

59:51D-glucose . We generally use D-glucose .

59:54So where will D-glucose be made from ?

59:56You can make it from D-glyceraldehyde .

59:58You cannot make it from

1:00:00L-glyceraldehyde , and our focus is

1:00:02generally more towards the D-form . So

1:00:04that is what is written here . Starting

1:00:06from D-glyceraldehyde we can only

1:00:08produce D-monosaccharides . Starting

1:00:10from L-glyceraldehyde we can only

1:00:12produce L-monosaccharides . Okay ? Next

1:00:14is amino acids . Now carbohydrates are

1:00:17covered . The major part of this was

1:00:19carbohydrates . This part is not that

1:00:21big . This is going to take less time .

1:00:23If I talk about amino acids , there are

1:00:25two groups . One we have is an amine .

1:00:27Okay ? An amine , that is the NH2 group ,

1:00:29and one we have is a carboxylic acid

1:00:31group . If you combine both of these , if

1:00:33they are present in a chain , like they

1:00:35are present in this structure . This is

1:00:37called an amino acid because both amine

1:00:38and carboxylic acid are present . Then

1:00:40we call it as amino acids . Now , if you

1:00:43look at these amino acids , we have to

1:00:44look at the same classification as to

1:00:46which is at which position . Like this

1:00:48one . Okay ? Suppose , with respect to

1:00:50this , the first is alpha , with respect

1:00:51to this , the second is beta . So it

1:00:52happens according to this . If it is on

1:00:54the first carbon , the alpha carbon , it

1:00:56will be called alpha-amino acids . If it

1:00:58is on the second carbon , it will be

1:00:59called beta-amino acids . If it is on

1:01:01the third , it goes on as alpha , beta ,

1:01:03gamma , delta , and so on . Okay ? So alpha

1:01:05, beta , gamma , delta , and so on , this

1:01:07is a classification based on position .

1:01:09We generally deal with alpha-amino

1:01:12acids . Next , based on number . If you

1:01:16have an amino group , we call it the

1:01:17basic group . Okay ? Keep this in mind ,

1:01:19the basic group . And if we look at the

1:01:22acidic group , if both are equal in

1:01:25number , we call it neutral , for example

1:01:28, glycine — one NH2 and one COOH . Okay ?

1:01:31If , let's say , I have more acidic

1:01:33groups , it's called an acidic amino

1:01:35acid . Like we have aspartic acid . It

1:01:37has two COOH groups and one NH2 group .

1:01:39And if , let's say , I have more basic

1:01:41groups . Like what happens in lysine ?

1:01:43Two NH2 groups , one COOH . So we will

1:01:45call them basic amino acids . So , based

1:01:47on their groups , if the acidic group is

1:01:49more , it’s acidic ; if the basic group

1:01:51is more , it’s basic ; if both are

1:01:53equal , it’s neutral . This is our

1:01:54second classification . Now , let's move

1:01:57to its properties . Look at its

1:02:00structure , and by looking at it , you

1:02:02realize that there are some polar

1:02:05organic molecules , so we would expect

1:02:07organic reactions , just like other

1:02:09organic molecules . Right ? So the

1:02:12general perception is that these

1:02:14reactions will happen as they have been

1:02:16happening so far . Now the point is ,

1:02:18within these reactions , when we studied

1:02:21their properties , they are crystalline

1:02:24solids . That was not expected .

1:02:26Generally , organic compounds are not

1:02:27crystalline solids . They are colorless

1:02:29and odorless . Alright , that's fine .

1:02:31They are soluble in water . Highly

1:02:32soluble in water . This is a bit

1:02:34unexpected . High ionic character and

1:02:36dipole moment . This is also a bit

1:02:38unexpected . Okay ? Furthermore , high

1:02:40melting and boiling points . This is

1:02:41also unexpected . So , the properties are

1:02:44similar to ionic compounds . So , all

1:02:47these compounds you see , they lean more

1:02:50towards the ionic side . They are being

1:02:54duplicitous here . Huh ? Taking organic

1:02:56structures and organic chapters , but

1:02:58behaving like ionic compounds . How is

1:03:00that possible ? Huh ? So now we need to

1:03:02understand this . What is the reason ?

1:03:04The reason is that in their own

1:03:06structure , this COOH , what kind of

1:03:07group is it ? It is your acidic group .

1:03:10This is a base . So what is the job of a

1:03:11base ? To consume the hydrogen of the

1:03:13acid . That’s exactly what it is . So

1:03:14if it acts like this , what will happen ?

1:03:16An acid-base reaction will occur . So ,

1:03:18from that acid-base reaction , we get an

1:03:21ionic compound , right ? We have ions now

1:03:23. Huh ? So , it shows a lot of ionic

1:03:25nature because of this . Because it is

1:03:27existing as ions . This is called a

1:03:29zwitterion . Or some people call it

1:03:31bipolar , meaning two poles have

1:03:32appeared . Negative , positive , bipolar

1:03:33ion . So , what is a zwitterion or

1:03:35bipolar ion ? It is the behavior where ,

1:03:38in your life , compounds that contain

1:03:40both acid and base groups — like in

1:03:43amino acids — will react by themselves .

1:03:46If they have reacted , what happens ?

1:03:47Plus and minus charges are existing .

1:03:49Charges are existing . Because of that ,

1:03:51it is able to show more ionic nature .

1:03:53Now the point is , which ones do we have

1:03:55to deal with ? We have to do alpha-amino

1:03:58acids . Okay ? Uh , one second . The slide

1:04:02got messed up . Why didn't this copy

1:04:04completely ? Just one second guys . I

1:04:11don't think this is fully covered . No

1:04:13problem , I will get this covered . Okay ?

1:04:15Let's do it . I will get this set in the

1:04:17notes . Let's talk about alpha-amino

1:04:18acids . There are two types of

1:04:20alpha-amino acids in our life . Okay ?

1:04:22One is called essential amino acids .

1:04:24One is called non-essential amino acids

1:04:26. Essential amino acids are those that

1:04:29your body itself , what do you say ?

1:04:30Cannot make . Our body cannot make some .

1:04:33Okay ? So , the ones it cannot make are

1:04:35called essential . Meaning you will have

1:04:36to take them from your diet . You will

1:04:37have to take them through food . And

1:04:39there are non-essential ones that you

1:04:40can make in the body . They are optional

1:04:42in the diet . Take them or don't . It

1:04:44doesn't matter . Okay ? They will be made

1:04:46by the body . Now we have a table

1:04:47provided here , which got messed up .

1:04:50Because the table couldn't print fully .

1:04:52Okay ? Look here , something strange has

1:04:54been printed . Bizarre . No problem . I

1:04:56will get it replaced in the notes .

1:04:58Don't worry . In your NCERT , there is a

1:05:00table like this . Something printed .

1:05:02Nothing happened . Such a table , a table

1:05:04like this is given . Check it once in

1:05:06your NCERT . I will get these slides set

1:05:09. We will have to go through this . This

1:05:12is something that we need to remember .

1:05:14I will tell you the basis on which this

1:05:16table is made . So , your amino acids are

1:05:19like this . Right ? They are like this .

1:05:21Let me do this . That is COOH here and

1:05:24NH2 here . We have hydrogen here and I

1:05:27will take this group as G. By replacing

1:05:29this G group , what is being said here ?

1:05:32Right ? If you put this in place of the

1:05:34G group , it is called isoleucine . Put

1:05:36this one , it is called arginine . Put

1:05:39this one , it is called lysine . In this

1:05:41way , and so on , you have all these

1:05:42groups . Right ? By replacing the G group

1:05:45, all your amino acids are formed . Now ,

1:05:47yes , I have brought this entire NCERT

1:05:49list here . I will have it corrected for

1:05:51you because this slide didn't come out

1:05:53right . So what you need to do is you

1:05:55just have to replace the G group . One

1:05:58more thing , these have some short names

1:06:01. Where there is a star , star means

1:06:03essential . No star means non-essential .

1:06:06Keep this in mind . Secondly , if you

1:06:09look inside , they have these short

1:06:11names . Like here you see , lysine has a

1:06:14three-letter word . You can represent it

1:06:17as LYS , Lys . Yes . And in the same way ,

1:06:20an alphabet is assigned to it . Right ?

1:06:21These are just your designations for

1:06:23which amino acid it is . Just its short

1:06:25name and its single-letter code name .

1:06:27This is how they have done it ?

1:06:29Differentiated it . I will bring the

1:06:30correct slide , so it will be fully

1:06:32verified for you . Don't worry . Right ?

1:06:35That will be verified in your notes .

1:06:36Similarly , you have others . Total there

1:06:38are 20 . Yes . So you see , these are all

1:06:41your structures . Like here comes

1:06:43Tryptophan , TRP , W is its short form .

1:06:45One-letter alphabet . Right ? It's okay .

1:06:48They made a typo in the slide . Let's

1:06:51move on . Next is inside this . Glycine

1:06:53is the only amino acid which is

1:06:55optically inactive . What is glycine ? I

1:06:57think the structure is not made here .

1:06:59Glycine should have been made first ,

1:07:00right ? Anyway , no problem . I will make

1:07:02it here . I will show you how to make

1:07:04glycine first . Right ? Glycine is made

1:07:06like this , brother . Right ? COOH here ,

1:07:08NH2 here , hydrogen here . This is common

1:07:11for everyone . The G , if you make it H ,

1:07:13then this is called glycine . Right ?

1:07:15This is your glycine structure . So ,

1:07:17that is what we are saying about

1:07:19glycine , since there are two hydrogens ,

1:07:21it is achiral because both of them are

1:07:23the same . If anything else other than

1:07:25hydrogen is there , like any R group , or

1:07:27whatever you attach , what will happen

1:07:29in its place ? Right ? If you take

1:07:30something other than glycine , like

1:07:32alanine . Right ? If the position of OH

1:07:34is different . Like , if we take methyl .

1:07:36Then what will happen ? If these groups

1:07:37are different . So , can I call this

1:07:39position chiral ? I think I can . Because

1:07:42this is different , this is different ,

1:07:43this is different , and this group is

1:07:44something other than hydrogen . So ,

1:07:45because of this , we say that glycine is

1:07:48the one which is what ? Your optically

1:07:51inactive . All the rest are your

1:07:53optically active . Most of the amino

1:07:55acids present in the human body are

1:07:57L-amino acids . So , as I said , if you

1:08:00look at the form , if NH2 is on the

1:08:02right side , it is D. If NH2 is on the

1:08:04left side , it is L. So , our body ,

1:08:06glucose was generally in D-form , but

1:08:08our body accepts more of the L-form for

1:08:11amino acids . So , this is in front of us

1:08:14. Now , sir , what exactly do these amino

1:08:16acids do ? For that , you make a body

1:08:19shot , right ? If I talk about a body

1:08:22shot , you eat protein , we have a lot of

1:08:25protein in your body as well . Actually ,

1:08:29protein is the final byproduct of amino

1:08:31acids . In the sense that if you join

1:08:33amino acids . Let's think backward first

1:08:36. If you break down protein ,

1:08:38polypeptides are formed . If you break

1:08:40down polypeptides , peptides are formed .

1:08:42If you break down peptides , alpha-amino

1:08:44acids are formed . So , if I join

1:08:46alpha-amino acids , a peptide will be

1:08:48formed . If I join peptides , a

1:08:50polypeptide will be formed . If I join

1:08:52polypeptides , then I will have protein .

1:08:55So , what is protein ? Nothing . Joining

1:08:58together many alpha-amino acids . Its

1:09:01polymer is what we call protein . So ,

1:09:04the protein you see or eat , what is it

1:09:06all about ? It is amino acids in the end

1:09:08. Right ? Sometimes , if you have heard ,

1:09:11those of you who go to the gym , have

1:09:14you heard of BCAA in the gym ? BCAA ,

1:09:16that is Branched ... That is Branched

1:09:19Chain Amino Acids . Right ? You must have

1:09:23heard , take leucine , take isoleucine ,

1:09:25take valine . You must have heard of

1:09:27these . Right ? What they do , for

1:09:29glutamine . Many people say , take

1:09:31glutamine . So what are these things ?

1:09:33Take a look , here are the structures of

1:09:35all of these . All right ? So whether

1:09:36anyone else reads it or not , gym-goers

1:09:38must be listening . Now we are talking

1:09:40about protein , sir , right ? Let's see

1:09:43further . All this is done . Yes , so how

1:09:45is the bond formed ? They call it

1:09:47peptization or something . What actually

1:09:48happens , brother ? Listen , we have to

1:09:50remove water here too , like an acid on

1:09:52one side and a base on the other . So if

1:09:54you remove water from inside here , okay

1:09:56water , if you remove water , then what

1:09:58will be formed ? From here , we'll just

1:10:00do it like this . All right ? If you look

1:10:02at it , if I write it like this and

1:10:03remove one H , then water will be

1:10:05removed from here . Yes . If water is

1:10:07removed , then what will happen ? Upon

1:10:08removing water , I have removed the

1:10:09water here . So my linkage will be

1:10:11formed like this . So the link that is

1:10:13formed , this bond is called peptide .

1:10:15Remember , in that one , a glycosidic

1:10:16linkage was formed . The bond that is

1:10:17formed here in proteins , what do they

1:10:18call it ? In amino acids , this is called

1:10:20a peptide bond . So this peptide bond

1:10:22was formed . Listen to one more thing .

1:10:24If I have two units . If there were two

1:10:27units , then from two units , how many

1:10:29peptide bonds am I forming ? One peptide

1:10:32bond is formed . And as many peptide

1:10:34bonds are formed , one water molecule is

1:10:36released accordingly . Are you seeing it

1:10:38? So an amide linkage formed by the

1:10:40combination of two or more alpha amino

1:10:42acids is called a peptide bond .

1:10:43Whatever is being formed . This is it ,

1:10:45one will be formed from two . If there

1:10:47were three , two would be formed . If

1:10:49there were four , three would come . If

1:10:51there were 10 , then nine would come . So

1:10:53accordingly , I have made this that if

1:10:55there are two units , then it forms one

1:10:58peptide bond and one water , if three ,

1:11:00then two , so on , if you have n units

1:11:02then n - 1 peptide bonds will be formed .

1:11:05n - 1 water molecules will be released .

1:11:08All right ? Now let's talk about what's

1:11:10inside . That is regarding , here comes

1:11:13globular protein . What has been done

1:11:15inside this ? All right ? It's a complete

1:11:18mess . Look brother , we have two types

1:11:19of proteins . All right ? Let's see the

1:11:22bifurcation of proteins . One is fibrous

1:11:25, the other we have is globular . We

1:11:27need to see the difference between

1:11:29fibrous and globular because these

1:11:30questions have appeared . First of all ,

1:11:32let's come to the force of attraction .

1:11:33It contains hydrogen bonding and

1:11:35sulfide linkages . Inside this , hydrogen

1:11:37bonding , sulfide linkages ,

1:11:39dipole-dipole , and van der Waals forces

1:11:41all exist . If you look at the molecules

1:11:44, the molecules here are long , thin ,

1:11:46linear , and lie side by side to form

1:11:49fibers . So , fibers are long and fibrous

1:11:52, whereas you see , what happens in

1:11:53globular ? They exist in three

1:11:56dimensions in a spherical shape . If you

1:11:58look at examples like collagen or

1:11:59keratin ; keratin is found in your hair .

1:12:01Right ? And if any of the girls here

1:12:03have heard about getting a keratin

1:12:05treatment . It’s related to this very

1:12:07thing . Myosin . What is myosin found in ?

1:12:09In muscles . You already know this .

1:12:12Similarly , if I talk about globular ,

1:12:13then hemoglobin , insulin , enzymes — all

1:12:15these have what ? Globular protein , man .

1:12:19Solubility in water : this is insoluble .

1:12:21Ever thought about that ? Huh ? Body

1:12:23built in the gym . We went for a shower ,

1:12:26and then the whole body washed away .

1:12:28That doesn't happen , right ? So it's the

1:12:30muscles , or let's say our body . Went to

1:12:32wash hair , and then all the hair fell

1:12:34off . That doesn't happen , right ? That

1:12:37certainly doesn't happen . So therefore ,

1:12:39what happens ? Just one second . Yes ,

1:12:44brother . So as I said about hair , have

1:12:46you ever gone bald ? No , right ? So , for

1:12:48keratin in hair , just remember that it

1:12:51is insoluble . If I talk about this side

1:12:52, what are these ? Soluble . Looking at

1:12:55roles , collagen in bone and cartilage .

1:12:57It strengthens your bone structure .

1:12:59Keratin in fingernails and hair . Right ?

1:13:01This is where they are present .

1:13:03Basically , these are human body parts ,

1:13:05in the sense that they are important

1:13:07proteins . I mean , some of you think

1:13:10protein is dangerous . This protein ,

1:13:12that protein ; it's not like that .

1:13:14Protein is involved in many things in

1:13:17your human body . So you should take a

1:13:19balanced diet . The diet has a role here

1:13:21. That is why all this is being

1:13:22explained . Right ? Besides , it is in

1:13:24metabolic enzymes in all organisms .

1:13:26Plasma , protein , antibodies , etc. ,

1:13:27these are the functions of globular

1:13:28protein . Right ? Let's move to the next .

1:13:31Now there is a structure . It is called

1:13:32this . Now , this also has two parts .

1:13:34Right ? Alpha helix and beta-pleated .

1:13:36Now look , man . What is the primary

1:13:38structure ? You have structures . There

1:13:40are four structures . One is primary .

1:13:42Right ? There is secondary , there is

1:13:44tertiary , and there is your quaternary .

1:13:46Among the structures within a protein ,

1:13:48let's first talk about the primary

1:13:50structure . So , all these amino acids ,

1:13:52look , are linked like this . They are

1:13:54linked like this . Linked in a chain . In

1:13:56a single chain . Yes . If it is a single

1:13:58chain , it is called primary . A linear

1:14:00chain is coming your way . But what if

1:14:02this chain starts to fold ? For example ,

1:14:04one option is that it starts folding

1:14:05like this . It starts folding like this .

1:14:07That is one option . It starts to fold

1:14:09in this way . So , if it starts folding

1:14:10like this , then what kind of bonding

1:14:12could be in it ? It could be

1:14:13intermolecular . Like this one , okay ? It

1:14:16is folding in this way . This structure

1:14:17you see , it is somehow a helical

1:14:19structure . It's like an alpha helix ,

1:14:20right ? This is called an alpha helical

1:14:22structure . Another structure is that it

1:14:24folds into a sheet . Like , look here , A1

1:14:26, A2 , A3 , A4 , these structures form a

1:14:29sheet like this . This is called a

1:14:31beta-pleated sheet . So , this is

1:14:33beta-pleated . This is beta-pleated .

1:14:36This is called an alpha helix . So , this

1:14:38is called an alpha helix . Okay ? This is

1:14:40your alpha helix . We are moving into

1:14:42two dimensions here . So , which

1:14:44structure is this ? It is its secondary

1:14:45structure . Okay ? Two-dimensional

1:14:47structure . Now , if we connect them

1:14:49further , if we connect these two

1:14:51further , then what starts to happen

1:14:54here ? When it goes into three

1:14:55dimensions , it starts to get a bit

1:14:56messy . You will see forces like van der

1:14:58Waals , dipole , hydrogen bonding ,

1:14:59disulfide linkage . So , these are your

1:15:01tertiary structures . If you connect

1:15:02them further , you get your quaternary

1:15:04structure . So , this is the quaternary

1:15:05structure . Like how the structure of

1:15:07hemoglobin was made . So , the main

1:15:08things like hemoglobin are formed from

1:15:10the quaternary structure . But yes , in

1:15:13the end , if you hydrolyze or segregate

1:15:15everything , you ultimately get amino

1:15:17acids . Okay ? And if this is clear to

1:15:21you , then next comes the denaturation

1:15:23of protein . Okay ? This is basically

1:15:25denaturation . So , I will write it here .

1:15:27This is the denaturation of protein . If

1:15:33you talk about it here , the structure

1:15:35of a protein , brother , look , a protein

1:15:37is something that works only as long as

1:15:40... It has some rules . I have explained

1:15:42the rules for every protein to you . It

1:15:45works only as long as , well , consider

1:15:48it must maintain its structure . I mean ,

1:15:52it must remain correct . If the

1:15:54structure gets messed up , it's gone .

1:15:56Right ? Or its biological activity is

1:15:58lost . So the point is , if you don't

1:16:01keep the protein in its structure or

1:16:03tamper with it , it is going to lose its

1:16:05biological activity . So it is written

1:16:08that for a protein , we call this the

1:16:09native state . Now , the protein has a

1:16:12structure . Okay ? That is called a

1:16:14native protein . If it is in its native

1:16:16form and you make changes like altering

1:16:18temperature , chemical reactions , or pH ,

1:16:21what happens ? The structures start

1:16:22opening up . The protein gets uncoiled .

1:16:24Like , if we saw this , what was it ? See

1:16:26these structures , if they start opening

1:16:28, the structure loosens . From 4 , it

1:16:30came to 3 , to the tertiary level . Then

1:16:33beta-pleated , it came to 2 degrees . It

1:16:35starts breaking down . So if that starts

1:16:36happening , its biological activity is

1:16:38lost . Protein loses biological activity

1:16:40. This is called denaturation . And

1:16:42during denaturation , the protein gets

1:16:43ruined . One more thing , this question

1:16:45has appeared many times . When

1:16:47denaturation occurs , keep in mind that

1:16:49the secondary and tertiary structures

1:16:51are always destroyed . But the primary

1:16:54structure remains intact . This is

1:16:57important , that during denaturation ,

1:16:59the primary structure is saved .

1:17:01Everything else is destroyed . Some

1:17:03examples are coagulation of egg ,

1:17:05curdling of milk . These are the

1:17:07examples of denaturation . Right ? So ,

1:17:10this is done . Now , with this , protein

1:17:12is also finished . Now , there are some

1:17:14small parts . Vitamins , enzymes , DNA ,

1:17:17RNA . These are small parts . These are

1:17:19theoretical parts . Again , you will have

1:17:21to read NCERT in-depth here . Okay ?

1:17:23Carbohydrates and proteins were the

1:17:25ones that needed some explanation .

1:17:27These enzymes and such things are very

1:17:29theoretical . Okay ? Go through the NCERT

1:17:31. I will explain at a high level .

1:17:33Enzymes are biocatalysts . What is the

1:17:35role of a catalyst ? Speeding up or

1:17:37slowing down reactions , depending on

1:17:39the type of reaction . So , things that

1:17:41do this inside the body are enzymes . So

1:17:43, the catalysts that are biological are

1:17:45enzymes . What are they ? They are

1:17:46globular proteins . They have ' - ase ' at

1:17:48the end . For example , the enzyme that

1:17:50acts on invert sugar is called

1:17:52invertase . Maltase acts on maltose .

1:17:54Urease acts on urea . So , the ones

1:17:57ending in " - ase " are your enzymes . How

1:18:00do they work ? They work using a lock

1:18:02and key mechanism . It comes , fits into

1:18:04its spot , does the job , and then moves

1:18:06out . So , they work on a lock and key

1:18:09mechanism ; a small amount is needed

1:18:11because once used , they can be used

1:18:12again . And yes , they work at a specific

1:18:16temperature . Because , for example , your

1:18:18body temperature is often affected . Yes

1:18:20. Then the functioning of these enzymes

1:18:21can get impaired . So , at very high or

1:18:23low temperatures , they are not going to

1:18:24work well . Okay ? So , that's about

1:18:27enzymes . Next is vitamins . So , what are

1:18:29vitamins ? Things the body needs in

1:18:32small amounts , obtained through diet ,

1:18:34so that we function and grow properly .

1:18:36For instance , if we have vitamin A , and

1:18:38you don't eat it properly , you get

1:18:39night blindness and such . Okay ? If you

1:18:41don't eat vitamin C , you get scurvy .

1:18:43Your gums start bleeding . So , these are

1:18:46things that mean vitamins are needed .

1:18:49If you don't take them in your diet ,

1:18:50you get deficiency diseases . Okay ? So ,

1:18:53you have to take them . This is what we

1:18:54call a balanced diet — that it has

1:18:56proteins , carbs , fats , along with your

1:18:58vitamins and minerals . On this , a whole

1:19:01... yes , take a look at this : which ones

1:19:02are fat-soluble ? Vitamins A , D , E , K.

1:19:05These are called fat-soluble vitamins .

1:19:07And which are water-soluble ? Vitamins B

1:19:10and C. So , all the B vitamins and all

1:19:11the C vitamins , what are these ? These

1:19:14are water-soluble . Okay ? These are your

1:19:16vitamins . There is a table in NCERT

1:19:18about this , which you must have surely

1:19:20done in your science exams during

1:19:21childhood . Where do you get vitamin A

1:19:24from ? Which disease do you get if you

1:19:25don't take it ? So , you will have to go

1:19:27through this table once . Don't argue ;

1:19:29you have to study with me . Okay ? So , go

1:19:32through this table . You will find this

1:19:34table in the NCERT . Remember this . Now

1:19:36we come to the last one , which is

1:19:38nucleic acids . There is a small part in

1:19:39this . Let's look at this and cover it .

1:19:42Look , your cell . Inside the cell is the

1:19:46nucleus . Inside the nucleus are

1:19:47chromosomes . Inside the chromosomes is

1:19:49DNA . If you notice , your features look

1:19:51very similar to your mom and dad . What

1:19:53is the reason for that ? Because genetic

1:19:54information is being passed on . Your

1:19:56DNA is a major reason for that genetic

1:19:58information being passed on . And we are

1:20:00now going to study this very DNA . What

1:20:02is it ? First , let's look at their

1:20:04structure , DNA and RNA . What is RNA ? It

1:20:06is a sugar . This is Beta-D-ribose . Okay

1:20:09? And what is DNA ? It is somewhat

1:20:11similar . If you look at the

1:20:12Beta-D-ribose , you just have to take

1:20:14this structure . In that , add 2 - deoxy .

1:20:16Now , what did you do , sir ? I'll explain

1:20:18. Take Beta-D-glucopyranose . Instead of

1:20:22making you memorize something new , do

1:20:24one thing : take this structure and

1:20:25remove the third number . Remove this ,

1:20:27and whatever is left behind is what we

1:20:30call Beta-D-ribose . There is no need to

1:20:32memorize a new structure ; I have

1:20:34already taught you Beta-D-glucopyranose

1:20:36, so this becomes Beta-D-ribose . If you

1:20:38want to make Beta-D - 2 - deoxyribose from

1:20:40ribose , if you want to make DNA , what

1:20:42do you need to do ? You have to remove

1:20:44the oxygen from the second position . If

1:20:46you remove it , you will see what forms ;

1:20:47hydrogen will take its place . You

1:20:48removed the oxygen from here , you

1:20:50removed this oxygen here , you removed

1:20:51it from here , so what remains ? Hydrogen

1:20:53. This is Beta-D - 2 - deoxyribose . Yes .

1:20:56That's why it is written " 2 - deoxy " at

1:20:58the second position . That is what it

1:21:01means . So , these are the structures you

1:21:02have . Yes . I have created these sugars

1:21:04for them . So , the sugars that come in

1:21:06RNA , and in RNA and DNA there are

1:21:08multiple parts . So , this sugar is

1:21:10formed in this way . Now let's look

1:21:12further . Okay ? Next , let's understand .

1:21:15Now , there are bases in this .

1:21:16Understand this once . Which are the

1:21:18nitrogen-containing bases ? We have a

1:21:20total of five . Adenine , cytosine ,

1:21:22thymine , uracil , guanine . Remember

1:21:25these short forms . A , G , C , T , and U.

1:21:28In your DNA , adenine , guanine , and

1:21:32cytosine are the same . Thymine comes

1:21:35separately . In RNA , adenine , guanine ,

1:21:37and cytosine are the same . In this ,

1:21:38uracil comes separately . So , if you

1:21:40want to see the difference in their

1:21:41bases , what is it ? DNA has thymine , and

1:21:45RNA has uracil . We will talk about the

1:21:48nucleoside and nucleotide within them ,

1:21:51because there are three things : sugar ,

1:21:53bases , and their structure . Okay ? Now ,

1:21:56understand what nucleoside and

1:21:58nucleotide are . Here , there is a sugar .

1:22:01To that , you added a base . Where should

1:22:04you connect it ? At C1 . You have seen

1:22:06the sugar , the one I taught you before .

1:22:08So , this sugar is what you have in full

1:22:10. What will you connect to C1 ? Its base

1:22:13will be connected like this . This is

1:22:15called a nucleoside . If you are talking

1:22:17about a nucleotide . In a nucleotide ,

1:22:19your phosphate group comes separately .

1:22:21So , it is the same up to here . The

1:22:22sugar needs to be connected to the base

1:22:24at C1 . But where will you connect the

1:22:26phosphate group ? At C5 . So , this was

1:22:28the sugar . The base is connected to C1 .

1:22:30You have to connect the phosphate group

1:22:32to C5 . So this is called a nucleoside .

1:22:34Nucleotide . Now the nucleotide can be

1:22:36connected further . Okay ? You can

1:22:39connect this further on . Like , if you

1:22:41look here , what did you do with this

1:22:43nucleotide ? You connected it further .

1:22:44So where did you connect it ? At C3 - C5 .

1:22:47So , you connected its C5 to this C3 . So

1:22:50this linkage is formed . This linkage is

1:22:52called a phosphodiester linkage . What

1:22:54did you do with this linkage ? You

1:22:56combined two nucleotides . This is

1:22:58called a dinucleotide . Now this

1:23:00continues in the same way . Di , tri ,

1:23:02tetra , and so on , it keeps continuing .

1:23:05And this is given to you like this in

1:23:06the NCERT . These complete structures

1:23:08have been drawn . The same thing I just

1:23:09explained , you will see it like this in

1:23:10the NCERT . Okay ? Next is , what will a

1:23:13polynucleotide be ? Combine them further

1:23:16. Go from di to tri , tri to tetra , and

1:23:18eventually to poly . So it will be like

1:23:19this . There will be a base and sugar .

1:23:21After that , the base group and

1:23:23phosphate . Sugar-base-phosphate , and

1:23:24keep repeating sugar-base-phosphate . In

1:23:26this way , your entire linkage is formed

1:23:27. This is a polynucleotide . This is it .

1:23:29This is what needs to be continued on a

1:23:31very large scale . That is how you are

1:23:33going to get a polynucleotide . Now , the

1:23:35main question on DNA and RNA will come .

1:23:37Differentiate between them . So , draw

1:23:38this for it . Okay ? Mention which sugar

1:23:41it is . Okay ? State the full form

1:23:43completely . This is called

1:23:44Deoxyribonucleic acid . That is called

1:23:46Ribonucleic acid . Yes . What are the

1:23:48bases here ? Here , this controls and

1:23:50creates the protein . This is the

1:23:52controlling one that is going to create

1:23:53the protein . It has a double-stranded

1:23:55helical structure . It has a

1:23:56single-stranded helical structure . So ,

1:23:58this is the structure of DNA you have .

1:23:59Just look at one thing in this . There

1:24:02is a hydrogen bond in cytosine and

1:24:03guanine . For one , they form three

1:24:04hydrogen bonds between them . There are

1:24:06two in adenine and thymine . That is all

1:24:08from here . Apart from this , there is

1:24:10the hormones part . Let me change the

1:24:12slide for a second . Okay ? Go through

1:24:14this hormones section once . Okay ? As

1:24:16for the rest , I will get the PYQs added

1:24:18and modify the slides a bit , because

1:24:20there are some issues in the slides , so

1:24:23I will get them fixed . But on a broad

1:24:25level , that is the chapter . With this ,

1:24:28your entire Organic and complete

1:24:30Chemistry is finished . This chapter is

1:24:32a bit theoretical . You must have

1:24:34understood that after studying it till

1:24:35now . So don't take the load . Everything

1:24:38will be done . Just need to read NCERT a

1:24:40bit for this . Read it properly two or

1:24:42four times . I have tried to explain

1:24:44everything in a crisp way in these

1:24:45notes from the point of view of

1:24:46understanding . So you will be able to

1:24:48go through everything . And with this , I

1:24:51will say all the best for your

1:24:53Chemistry exam if you are giving it .

1:24:56Besides , I have already told you that

1:24:58the question series has been planned

1:25:00for you . So we are going to do it with

1:25:02a bang . Yes . Make sure to complete

1:25:04these five lectures before them .

1:25:06Because we will practice those

1:25:08questions through this . I have tried to

1:25:11keep its duration short . Because you

1:25:14already have less time . So I have tried

1:25:16to provide you with maximum question

1:25:18practice in a short duration and after

1:25:20that everything will be covered . Now if

1:25:23you watch these five lectures properly ,

1:25:25Organic is in your hands and you guys

1:25:27will do great . Okay ? You are lions .

1:25:30That is all . This is your Nikhil Sir .

1:25:32Signing off . Bye-bye . And