Full transcript
0:00hello and welcome to another screencast
0:01where this time we'll be discussing some
0:05of the finer points of metabolism and
0:08energetics as well as carburetor
0:10carbohydrate metabolism just an intro
0:13here to the carbohydrate metabolism
0:15stuff but by the end of this hopefully
0:17you should be able to describe and
0:19explain the relationship between
0:20metabolism and energetics so they're
0:23related but different also looking at
0:26metabolism and the connection to aerobic
0:28respiration and in finally listing the
0:32basic steps involved with glycolysis
0:34citric acid cycle electron transport
0:37oxidative phosphorylation there so if
0:39you're an AP bio then you know a little
0:42bit more detail about this but we're
0:43just going to kind of go over some of
0:45the basics here so first off metabolism
0:48up here is all of the chemical reactions
0:53that occur inside of the body right and
0:55in this case instead of inside of a cell
0:57so we're concerned primarily here with
0:58the cells so this is all of the chemical
1:01reactions the two kind of basic chemical
1:03reactions that you have are catabolism
1:05and anabolism or an ab ilysm so the
1:10catabolism is the breakdown so you're
1:12taking larger things and making them
1:14smaller and anabolism is the building up
1:18of things making them larger more on
1:21that in just a minute the energetics is
1:24the transformation of energy in the food
1:27stuffs to ATP and heat right so these
1:30food stuffs this is why we are eating so
1:32these food stuffs are potential energy
1:37that the cell can't use directly but
1:40those potential energy will be converted
1:42into ATP which is the energy molecule
1:47the cell that is the the molecule that
1:49the cells are going to use to do all
1:50sorts of different different functions
1:52okay so the food stuffs that are going
1:57to go in or right here are these organic
1:59molecules right so when we ate the blue
2:04cake right we had proteins which will be
2:08digested down into amino acids we had
2:11fats or lipids
2:13and so the oils and fats and then simple
2:20sugars are the carbohydrates so those
2:25organic molecules are the things that go
2:27into the cells and so these are absorbed
2:31in the bloodstream and then also then
2:33transported into into the cells of the
2:36body right so these organic molecules
2:38come from food we eat also included in
2:45here are things like vitamins and
2:47minerals but these are the primary
2:50things that we want to focus on here so
2:53these organic molecules enter cells and
2:55they become part of what's known
2:57colloquially as the nutrients pool ok so
3:01these simple monomers here of amino
3:05acids and lipids and simple sugars are
3:07in this nutrient pool and when you
3:09combine them together they are used to
3:15number one maintain and repair the cell
3:18so that sells a busy place the carbs
3:22lipids proteins get used to maintain
3:26that growth cells will grow and divide
3:29we weren't always this size alright so
3:32we get larger we add more cells and that
3:36also helps with repair and when you
3:38damaged cells they will regrow
3:41themselves secretions as you know are a
3:43big thing so most secretions of the body
3:47of these cells are of protein base but
3:51it's not the direct protein that came in
3:52remember that the amino acids are coming
3:54in and that those will get put together
3:55to make the proteins those are the
3:58secretions like like hormones that get
4:01released neurotransmitters etc and then
4:04finally stored nutrient reserves right
4:07so the cell can pull from this nutrient
4:09at pull from the nutrient pool and
4:11create stored nutrient reserves and for
4:14example things like glycogen things like
4:18fat these are the two major major
4:23storage molecules for energy for you
4:26know
4:27the text says a rainy day so all of
4:29those things can also then be broken
4:33down in times of need so if the cells
4:35activity increases and the demand for
4:38ATP increases these substances here can
4:42all be broken down and enter re-enter
4:45what was called the nutrient pool and
4:47then enter this era anaerobic catabolism
4:52or aerobic metabolism here and we're
4:56going to focus primarily here on this
4:57aerobic metabolism so the amino acids
5:03the lipids the simple sugars can enter
5:06Arabic Arabic metabolism of which there
5:08are three phases two of which happened
5:11inside the mitochondrion here so this
5:13era of AG metabolism I of the of the
5:17energy potential energy that went in
5:18sixty percent is lost here as heat and
5:21is not usable by the cell and then
5:23another forty percent is used to make
5:25ATP and again this ATP this this
5:30anaerobic started this aerobic
5:32metabolism has converted the energy
5:34potential energy and these organic
5:36molecules into stored energy of ATP it's
5:40the big deal the big deal is that ATP is
5:42used to do all of these cellular
5:44processes that are important right
5:46moving cells contracting cells
5:50intracellular transports and moving
5:52stuff around the inside of the cell
5:53cytokinesis making new cells
5:55reproduction their endocytosis taking
5:58things in exocytosis secreting and
6:01removing things okay so might be a good
6:05idea just to kind of pause there and
6:07take a look at at this let me just do
6:10this for you here so this is the
6:12metabolism part there's all the
6:17reactions that take place the sum of all
6:19the reactions that take place inside the
6:21cell all the anabolic reactions and all
6:23the catabolic reactions right the
6:25energetics the energy flow is from these
6:28organic molecules here stored energy in
6:32the potential in the bonds of these
6:34organic molecules to the nutrient pool
6:36and then used here in Arabic respiration
6:40to make
6:41potential energy in the bonds of ATP so
6:44maybe you're going to do that there to
6:46pause and summarize that so this aerobic
6:53respiration sort of kind of a big deal
6:56and can be broken down into three main
6:59phases I'm not worried about all the
7:01details on this slide but cells are
7:03going to use aerobic respiration to
7:05produce this ATP the first phase is
7:08glycolysis this happens out in the
7:10cytoplasm where six carbon glucose
7:13molecules are going to be converted into
7:15these three carbon pyruvate molecules
7:18those pyruvates will then enter the
7:20mitochondria where the second main main
7:25phase here the citric acid cycle occurs
7:27the citric acid cycle is occurring
7:29inside the mitochondria the third main
7:32phase is the electron transport system
7:36so without this glucose without pyruvate
7:40you don't run the citric acid cycle
7:41without the center guess it's like oh
7:43you don't run the electron transport
7:44system the electron transport chain
7:47electron transport system is a big deal
7:49because look how much ATP is being
7:52produced here from one single molecule
7:56of glucose we get a lot of ATP molecules
7:59that are produced here in Arabic
8:01respiration not shown on the diagram is
8:04that this is aerobic because oxygen will
8:10be used to run this electron transport
8:13system again a lot more details here
8:16that we're not going over but just
8:19suffice it to say that i want to show
8:20you again that you are using organic
8:23molecules here glucose which is the
8:25example in this case right the store
8:28bonds in the potential energy stored on
8:30the bonds of this glucose molecule are
8:32ultimately via glycolysis citric acid
8:35and electron transport going to be
8:37converted into these ATP molecules over
8:40here the vent can be used to run the
8:42cell so this is the summary of
8:43energetics the energy transfer so want
8:50to just back up a second and now that we
8:52have this show you
8:54that it's not just glucose that is going
8:57to be used here right so this revisit
9:00this nutrient pool again inside of the
9:03cell this nutrient pool came from the
9:06amino acids and carbs and lipids that
9:15were in the blood that got into the
9:17blood from the GI tract so there's the
9:22GI tract and you'll be absorbed these
9:24things from the GI tract into the blood
9:26and then from the blood into the cells
9:29going up this way these are all anabolic
9:34reactions going up this way right so
9:36these fatty acids can be used to make
9:38triglycerides and this these
9:40triglycerides are fats that are stored
9:42glycogen is stored glucose and then
9:46using amino acids to make the cells own
9:48proteins again so those are all going up
9:52those are all anabolic reactions but
9:55that nutrient pool can also be used to
9:57make these small carbon chains here that
10:00will then be able to enter this second
10:03phase the citric acid cycle which is
10:05inside the mitochondria and because I
10:08can do the citric acid cycle that means
10:09I can do the third phase this electron
10:11transport system right and here's oxygen
10:15coming in and water is going to be
10:17produced as a by-product and then ATP is
10:20going to be me right over here so again
10:23this diagram is just showing you that
10:24these nutrient pools can be used either
10:26to do anabolic stuff or to do catabolic
10:31reactions here we can break them down
10:33break the bonds and use the use that
10:36potential energy to make ATP in aerobic
10:39respiration okay variation on the theme
10:44we're going to see this again and again
10:46and again cells use molecules absorbed
10:51in the digestive system to build up
10:53resources manufacturer cellular
10:55processes and run respiration pathways
10:57to produce ATP what you should see here
11:00again is get lipids carbs and proteins
11:07can be used in catabolic reactions to
11:10make fatty acids glycerol pyruvate these
11:14amino acids they can all eventually feed
11:16into this central system right here
11:20glycolysis the second one citric acid
11:24inside the mitochondrion and the third
11:26electron transport okay we're going to
11:29see this diagram a little bit more
11:31specifically when we talk about
11:32carbohydrate metabolism okay so
11:36hopefully here now you are able to
11:38describe the difference between
11:40metabolism and energetics talk to us a
11:44little bit about the relationship
11:46between metabolism and aerobic
11:48respiration and then identify and
11:50describe briefly here the three steps
11:52involved with Arabic respiration namely
11:55glycolysis citric acid and the electron
11:57transport okay thanks for listening and
12:00bring your questions of class