hi everyone and Welcome to our video on the topic of respiration so this video we will go through from the beginning to the end of the topic of respiration to keep unit 2 . Okay so just a little outline as to what this video will have in it so we'll be going through the four main steps in respiration which would be first glycolysis then the link reaction which is not essentially a big part of it but it's a very important part then we'll be going through the Krebs cycle and finally we have the electron transport chain but that's not all we'll be doing we'll be also doing anaerobic respiration which you would have heard about already and investigating the rate of respiration with an experiment all right so that will be our agenda for today's video all right so let's jump into glycolysis one time okay so I'm going straight to this diagram here all right so glycolysis occurs in the cytoplasm of the cell that's very important right it occurs and decidoplasm of the cell okay um so there are there are a few steps in glycolysis you can see from this diagram you know we have ABCDE and f as well right so these are very important so in E you can see that the glucose enters the cell so that's the cell membrane there and glucose enter this cell so that's the first step of diffusion all right and then once it's in the cell now you can see that glucose goes to glucose 6-phosphate and then fructose 1 6 is frosted by similar reactions using ATP so you can see ATP here is going to EDP ATP is going to ADP so 2 ATP are actually used up Manorama process of respiration is to make ATP so you know we better be making some profit after spending some ATP there right so these two steps are called phosphorylation and remember the change of ETP to ADP is called phosphorylation right so phosphorylation occurs twice right then B and C okay now once for this fructose 1 6 this phosphate the next step is lysis slices neutralizes means the split right so fructose 1 6 bisphosphate is actually split into two molecules called trius phosphate right so they are the same molecules triosphate so now each trials phosphate molecule will undergo the same reaction so essentially all your actions are now doubled okay all right so in Step e we have oxidation all right so the trials phosphate molecule is oxidized to this intermediate bisphosphate is not essentially essential to learn what that molecule this is just a intermediate molecule before we get to our final molecule right but in order for it to be oxidized NAD needs to be reduced so the opposite will happen to NAD and remember everything happens twice right so you end up with two reduced NAD molecules there all right and then in F now we have substrate linked cost for relation all right so again we have ADB changing to ETP all right so as you can see this substrate link phosphorylation occurs twice for each side all right so you have ATP being manufactured another ATP being manufacturers has two on that side and then two more here okay so therefore we manufactured four ATP glycolysis while we used two ATP up here for a net profit off to ATP molecules and that's not all we get in um in glycolysis we also get these reduced nads which will come in handy later on all right and you'll see why very soon all right now the end product of glycolysis is just very important molecule here I ruined so we also get two pyruvate molecules and that goes straight into the link reaction okay so before the Krebs cycle can begin pyruvate needs to be converted essentially right so in the link reaction you can see it here I rub it reacts with something called coenzyme a plus an NAD molecule to achieve this very important molecule here acetyl coenzyme e plus you got more reduced NAD and you get some carbon dioxide okay not very important the important things to note are yes and the reduced entity so we got reduced NAD and glycolysis and now we are getting more reduced NAD U link reaction okay now um coenzyme acetyl coenzyme e is very important in helping the reaction of a certain molecule called oxaloacetate which we will see in the Krebs cycle all right and that essentially starts the Krebs I could or that it could never okay so there's a little table here down here it says for each glucose molecule after the link reaction we got two carbon dioxide you need to know about that but we got two reduce NAD and two acetyl coenzyme a molecules so therefore remember everything that occurs after glycolysis occurs twice right for each pyruvate molecule right so therefore when we go to the Krebs cycle let me go to it here there are actually two Krebs Cycles occurring per glucose molecule because remember the glucose molecule is split in 32 trials phosphate molecules and you have two pyruvits all right so all these all is um steps occurred twice all right but we'll have one big summary as to how many ATP molecules we are making per glucose molecule right so you add up all basically right so that was the link reaction I I as I said not not too big there it's just to make the um acetalco enzyme here right so let's go to the Krebs cycle now the Krebs cycle unlike glycolysis occurs in The Matrix of the mitochondrion right glycolysis occurred in the um cytoplasm we sell okay right so now we have acetylicoenzyme here and we have oxal acetate oxaloacetes is a four carbon compound acetylcholenzyme is a two carbon compound so they are both going to react to make this six carbon compound called citrate okay so the important things to learn here in the Krebs cycle are the yellow boxes right we need to do enough these molecules here you don't need to learn the purple enzymes okay that's that's irrelevant basically but the blue stuff and the ATP stuff you also need to know as well as these green stuff down there as well we'll get to that okay right so that was the first step oxalo acetate combining with acetyl coenzyme to make citrate the second step is very simple citrate converts to isocitrate that's basically the same thing just an isomer of the other okay now isocitrate and the third step undergo is a dehydrogenation and decarboxylation reaction that might sound complicated but that's actually the same thing that happened to pyruvate in the link reaction let me show you so if I remove it was actually decarboxylated meaning it lost a carbon molecule right and I lost it via carbon dioxide and it was also dehydrogenated because an NAD became a reduced entities also called nadh as an accepted a hydrogen molecule so the pyruvate was also dehydrogenated meaning it lost the hydrogen there's also decarboxylated meaning it lost a carbon okay so nothing nothing too big there right so the isosce rate we say it's dehydrogenated and decarboxylated right and that forms Alpha ketoglutarate all right this one down here now whenever something is dehydrogenated and decarboxylated it loses carbon dioxide but again we are not we are not concerned about that you just breathe that out after you respire all right that's always product but what we do like is the reduced and AD being formed or nadh right so that's another one so you can see any process of respiration a lot of these nadhs pop up right right so let's continue now Alpha keep the glitter down here actually on Lagos more decarboxylation all right so this undergoes the same thing as M3 right so this is step four right so it's decarboxylated a succinyl coenzyme e and every time you decarboxylate you know we produce a an ADH so we like that all right you will see why that's very important afterwards okay Now sucks no coenzyme e and the fifth step forms succinate however it's not a decarboxylation reaction is actually substrate linked phosphorylation which we saw in glycolysis right so in substituting phosphorylation you know we make an ATP molecule so that's very important so you see that's the first ATP molecule we need in the Krebs cycle okay right so now we are at succeeding it kind of in the middle of the um of the Krebs cycle there right now socks in it goes to fumarit right and this is simply oxidized however there's no NAD over here instead to go to fumarit we use f80 it's not very important to know exactly the difference between NAD and fad but just know that it's reduced in this in the same way as nadh it's just fadh2 not just how the molecules right but the same process it's reduced okay so we had fun right now fumaritas simply converted into Malibu by adding water not very important day and finally in the eighth and final step to get back to oxalo acetate malit is dehydrogenated right to form oxaloacetate so again now we make another nadh molecule and we go back to oxaloacetate and there we will start over the Krebs cycle again right so this is the cycle it's simple steps you just simply need to learn how to draw it practice to draw it practice the lunar few molecules and you'll get there right so just a quick summary as to what was made in the scrap cycle we have one nadh two nadhs you have an fadh and we have three nadh molecules so we have three and ADH we have one fadh2 and we also have the ETP molecule one ATP molecule now this is poo pyruvate right every pyruvate molecule produces these three things however per glucose remember glucose makes two pyruvate all right so per glucose molecule will have six nadhs two fadh2 and two ETP molecules right so all these are produced in the Krebs cycle for one glucose molecule so now let me show you why nadh and fadh2 are important now we are at the final step in respiration called electron transport chain right it looks a little bit complicated but it's not that bad I will show you what I mean now so in the molecules nadh and fadh2 right they they consist of high energy electrons because they were just need right so the electrons in this these molecules are high energy so in the electron transport chain every Orange molecule here are called carriers right electron carriers so we start off with nadh reductase which is the highest energy electron carrier so all the high energy electrons from nadh and fadh are going to pass through nadh reductase and step down the gene like if they're going down a ladder and every time the electron goes down or wrong or moves to another molecule they lose energy right so the electrons lose energy and deform of ATP right so the electrons have a lot of energy to give so as they go down the ladder they keep giving off ATP keep giving off ATP and we like that and then finally so it goes down more and more carriers right so cytochrome is a popular carrier until it eventually binds the oxygen of all things and then it's being converts to water and it will be excreted in the body right so before it's excreted it makes a lot of ETP right and this is actually the whole purpose of breathing in oxygen in the body for just one reaction here at the end of the electron transport chain if you noticed for the whole of the topic of respiration we didn't see an oxygen molecule yet you might be wondering so well what what's the purpose of oxygen respiration this is the process here this is the only purpose of oxygen just to get rid of the electrons at the end okay so that's where the electron transport chain is about now the different molecules and ADH and fadh2 they give off different energies right so essentially for one nadh molecule sorry one nadh molecule gives off three ETP those electrons are very high energy okay one fadh2 molecule they give off two ATP molecules okay so just keep that in mind as to when the I have to go through the electron transport Gene so knowing this now we can actually calculate well how much ATP is actually made in respiration per glucose molecule okay so this is called the energy EU for aerobic respiration okay so we have glycolysis the link reaction Krebs cycle and the electron transport chain okay so let us do ATP first the actual ETP right so in glycolysis we um we made four ATP molecules there right now we we're not taking into consideration the um the fact that we used well we could actually do it as a net the net production ibtp right so remember we used 280p in the beginning of lycolysis but we made four so the net product of ATP and glycolysis is two molecules right in the link reaction we didn't have any ATP being made we only made the nadh molecule right so in the link reaction it made no ATP right and the Krebs cycle each Krebs cycle we make one ATP molecule I remember per glucose molecule we actually have two Krebs Cycles so in the Krebs cycle we make two ATP molecules there right um and then the electron transport chain well it kind of depends on the um the amount of nadh and fadh molecules there so we'll leave that out for now let's take a look at the nadh molecules being produced and then we'll calculate the electron transport chain right so in glycolysis we actually have a good bit right so let's see how much we have in glycolysis um if you really the passage here we can see that there are two nadhs being formed in glycolysis right so that's actually um put a try it with phosphate molecule right because if we go up back to the uh the glycolysis you can see that there's one I reducing ADH here another produce any DHS so for glucose molecule we actually have two nadhs being formed right so let's go down here and we could put two energies now I have to put the fadh2 here although there's nothing being in Legos this is just for the Krebs cycle right now the link reaction also has two nadh molecules being made all right let's go back up and check that so here we have the link reaction you can see we have a reduced nadh here and that's per pyruvate molecule so for the glucose molecule we have two pyruvate molecules so there's actually two reduce NAD being formed there all right so let's go back down so we have two nadh molecules they are now the Krebs Cycles responsible for making quite a lot of nadh molecules so let's count them we actually did the calculation already here all right so we have a lot of things being formed here another Super glucose molecule right so per glucose molecule we make six nadh and two fadh molecules all right so in the Krebs cycle we make six nadh molecules and two fadh molecules right and now we can actually use these two to calculate how many ATP the electron transport genomics nadh molecule we get three ATP molecules from so we have two from glycolysis two from the link reactions six from the Krebs cycle that is 10 nadh molecules so 10 by 3 I'll actually put it here ten by three that's City um ATP there right and then for the fadh2 we get two ATP per molecules so we have two of them so that's two by two which is four right so an electron transport chain we get a total of 34. TP molecules so it's a totally top now a total amount of ATP in respiration per glucose molecule is 38 ATP so we got two from glycolysis two from the Krebs cycle and 34 from the electron transport chain so that's how we get 38 ETP per glucose molecule and aerobic respiration okay and that is the bulk of respiration there so let's just do a quick rundown of anaerobic respiration so in anaerobic respiration organisms can make ATP without the presence of oxygen so which means that there's no electron transport chain being involved there's no Krebs cycle it's really just glycolysis okay so without oxygen we cannot regenerate these the NAD and fad so you have to do something else to try to get them back right so the reactions of glycolysis you know makes two ATP molecules and organisms can survive on two or three molecules for some time right depending on what the organism is okay so in order to try to regenerate the nadnf video which you know is very important the pyruvate at the end of glycolysis is actually converted to something else depending on the um the molecule right so the pyruvate is said to be decarboxylated to ethanol right and this is in yeast it's also called alcoholic fermentation because of the presence of ethanol right and the enzyme that does this is pyruvate the carboxylase so you can see here the glucose goes the pyruvate Genesis glycolysis here you don't need to go back through the whole glycolysis right and then if I remove it now in the yeast cells undergoes alcoholic fermentation that makes ethanol and then that converts the ethanol plus carbon dioxide and then you get energy right so the carbon dioxide in a in alcoholic fermentation is what meets bread rice as well right so that is an application of of alcoholic fermentation and yeast that's all bread is meat right that's what bread Rises now let's take a look at anaerobic respiration and animals so it's it's very similar right except what happens to pyruvate at the end okay so in certain situations where you want ETP to be made quite rapidly right you will depend on anaerobic respiration and you know about this since form five right so glycolysis can happen very quickly um in without having to go through the um the whole electron transport chain with ticks quite some time right so even though it would Supply two ATP molecules it will take place quickly and you know since NAD will be regenerated it can keep going already glycolysis can keep going because your homoglycosis you need NAD right so in order for this to occur the pyruvate at the end of glycolysis here will undergo lactic acid fermentation to make lactic acid it has to do this in order to regenerate the NAD molecules all right that's what will keep the glycos is going however lactic acid or does the pH in the blood and remember you need your current phrase enzymes to to function and it is because the pH changes the enzymes will not function as they usually do and this is why you will feel tired after exercising rapidly for some time right now we can't Harvest lactic acid buildup so the body will eventually get rid of it and to do this it occurs in your liver right and it actually has to re-oxygenate um the the lactic acid so your body has to give oxygen to the lactic acid to get rid of it and this is actually called the oxygen debt this is why after exercising for so long you will have to breathe deeply and you know you have to take some deep breaths in order to catch back yourself that is called the oxygen debt all right so the final thing we'll be doing is actually looking at an experiment to measure the rate of respiration so in this experiment here we have this skill that is made up of our ruler all right then we have a little liquid droplets in your ruler sorry what will happen essentially is that air will push through the tube and will push the droplet to one side right and the more a that is pushing the you drop that the faster it will move and the more we could calculate your rate right um what you have in this set of the apparatus here right so you have your small organisms that will be undergoing respiration you have this sooner line all right so the soda lime has a very um has a very important function right so the soda lime will absorb the carbon dioxide that is being produced by the organisms right so you can't have the carbon dioxide pushing the droplet as well because then it will not um it um it would lead to errors in the experiment right so it is sweater line there absorbs all of the carbon dioxide now the cause is to Simply separate the organisms from the corrosive effects of the soil and if you if you put your organizational and you just die right so it goes there is important to separate the organisms from this pseudo line okay so in in this apparatus we have the air here as I told you right so air is all over here all right now remember respiration Arabic respiration uses oxygen so all this and all this over here is air that is available for these organisms to use so therefore if they are undergoing aerobic respiration they will be using oxygen and they will actually suck the um this droplet this way right and remember they will also be producing carbon dioxide which would have pushed the droplet back right because it would have been like an uh you use yeah but it's still breathing out a right that is the important function of the solar line so the pseudo line will absorb the carbon dioxide so therefore the oxygen will be used up and the organelles will not be putting out air to push back the liquid right so remember if they suck any liquid like a straw it looks like in the air out of the tubing like a straw the liquid is going to follow it because of the negative pressure and you will simply have to look at where the liquid was first where any relay it is and then after certain amount of time you measure where it is now so let's see you know after a few minutes it reaches here so you measure from here to here and you will see the distance that the um the liquid move you will have the time that you took for the liquid to move and therefore you could calculate you read any readers like speed right so therefore you use that way to to calculate the rate of the reaction it's very it's a very simple experiment a very easy one as well so you just need to learn how to draw it and the functions of the important parts of the apparatus right meaning the liquid the ruler being this scale is absorb the carbon dioxide and in fact that the organisms will be breathing in oxygen which is only available here and through the tubing right so as they use the oxygen is going to pull the liquid and therefore there we will get your measurements okay so I hope you guys enjoyed this video if I try to make it as short as possible because respiration is a long topic so you could go through it how many times you want and make sure you grasp topics okay bye everybody