Glycolysis - Metabolism

right today we are going to talk about glycolysis right and like pollicis how do you define glycolysis glycolysis is a metabolic pathway in which you break down the glucose into two molecules of pyruvate so basically this pathway is you break down the glucose through multiple steps right eventually into pyruvate and during this process when you are breaking the glucose into two molecules of pyruvate do two molecules of pyruvate some energy is released right some energy is captured as ATP and some energy is captured in the form of nad edge right now again what is the glycolysis like collets is is a metabolic pathway by which will break down the glucose into two molecules of pyruvate or pyruvic acid and during this process there is some form of formation of ATP there's more modest amount of energy released not big amount of energy because during glycolysis you release only a small amount of energy from glucose in the form of ATP and in form of NADH and NADH later on can be taken to the electron transport chain and there from this we should make more ATP and Piru pyruvate if yes mitochondria are available in the south and if oxygen is available in the cell then eventually pyruvate will enter into yeah Krebs cycle or citric acid cycle and lot of energy will be released but when we talk about glycolysis that is a pathway from glucose up to pyruvate right and if oxygen is not available if oxygen is not available or mitochondria are not present in a cell then we cannot take pyruvate into acetyl-coa and eventually we cannot take pyruvate into Krebs cycle then we take pyruvate into which side yes neck tip I said is that right so it means that during the glycol glycolysis right if oxygen is available if mitochondria are available the end product of glycolysis which is called pyruvate will be taken into Krebs cycle a lot of Energy's released and this type of glycolysis right in which pyruvate is formed in the end is called aerobic glycolysis but if oxygen is not there or mitochondria are not there then pyruvate is converted into lactic acid and when pathway moves into this direction we call it anaerobic glycolysis that is called anaerobic glycolysis this look like Allah says the break down of glucose into pyruvate this takes place in which cells Jill this reaction occur in which cells Guerry all cells all the tissues have a capability to break down the glucose into pyruvic instead of pyruvate as the right and most of the tissue have also capability to break down to advance the pyruvate into as a child koay and most of the tissues will eventually take it to krebs cycle if oxygen is available and mitochondria are there but is there any cell which does not have mitochondria less than my question carefully is there any type of cells in your body which do not have mitochondria and even if oxygen is there even if oxygen is there because mitochondria are not not there those cells cannot take this into Krebs cycle those cells have to take the pyruvate to lactate again listen my question is is there any type of cells in the body in which mitochondria are not there and even if oxygen is there pyruvate due to absence of the mitochondria we cannot do the aerobic glycolysis so we have to move to the electric I suggest somebody which cells red blood cells excellent so someone knew the answer there red blood cells red blood cells right they have what type of glycolysis anaerobic glycolysis even though red blood cells of lot of oxygen you know red blood cells of hemoglobin and hemoglobin has oxygen but red blood cells themselves don't utilize oxygen the good news is that they are very honestly transporting oxygen from the lungs to the tissue and for their own metabolism the don't utilize oxygen they are very honest transporters the very honest transporter of oxygen because red blood cells don't have mitochondria even though they have oxygen attached with the hemoglobin but because they don't have mitochondria from in red blood cells pyruvates are converted into lactate am i clear now another thing i told you that glycolytic pathway operates in every cell it most of the enzymes or rather than enzymatic pathway or multiple enzymes which are involved into this pathway these enzymes are present in which part of the cell yes please madam laura she is going to tell us that which part of the cell has all the enzymes available for the glycolysis in the cytosol that's great so in the cytosol you break down glucose into pyruvic acid because of multiple enzymes involved in this pathway and all those enzymes are present in cytosol so we can say the like kinetic pathway or glycolysis is a cytosolic pathway right this is a site of solid pathway now any cell any Cell which is going to do glycolysis what will be the first step any cell which is going to be involved in the process of glycolysis any cell which want to get energy by the breakdown of glucose into pyruvate what will be the first step okay further fizz telling us what should be the first step what is the first step yes Patrick yeah we're too close these things well he knows first of all that cell has to get the glucose is there right it is same thing if I ask you you're planning for shopping where - the first step to get the money in your pocket is the right in the same way when cells are going to do like Alice's when they're going to break down the glucose the step number one is they should get the glucose is there right and sell there of course getting glucose from extracellular environment and from the blood right so the first step when we will talk about is that how you Lucas is transported from the blood and extracellular environment into the Sarah once glucose is transported inside the cell then truly glycolytic pathway starts so first we'll talk about transport of glucose when we talk about the transport of glucose all of you must be knowing that glucose is primarily coming from yes from over light-rail down of the carbohydrates right monosaccharides and eventually from here it is coming to the portal which circulation portal circulation and portal circulation is going to yes place liver right so glucose is coming from GI teat is being absorbed through the portal circulation it is coming to the liver and in the liver there are hepatocyte s-- right there are parasites the cells of the liver right and eventually blood is entering into liver as portal what is this portal vein passing through the liver areas right and these vascular channels are surrounded by liver cells and eventually this blood will go out of the liver and now it is going to general circulation it is going to yes please general circulation now this point is very important to understand this particular pathway because when you take a heavy meal especially the meal rich in carbohydrates very large amount of glucose is absorbed and it is very important to understand then when a very big amount of glucose is absorbed vada from the GI t into portal circulation liver cells are specialized in extracting the glucose right liver cells are specialized I will talk later how they will take up lot of glucose right and store it and store it and only a small amount of glucose will go to the general circulation what is the benefit of this the benefit of this strategy is that lot of glucose which is coming right out of it most it is taken up by her parasites or cells of the liver so that after the mean amount of glucose which is reaching to the blood it does not produce very high level of glucose right so it does not produce hyperglycemia is it right and of course when in between the meals when glucose is no more coming from here the right when jgit is not absorbing glucose before the meals you can say when you are in a fasting state right at that very time amount of glucose here is very less I am later on biochemistry you will learn then liver as liver cells are capable of releasing the glucose back to circulation and advantage of this situation is that in the fasting state blood glucose level does not drop dangerously so how the liver is working liver is working as the glucose bank right when there's extra glucose never cells will take up the glucose and when the deficient glucose they will release the glucose but one point which is very important to understand that most of the monosaccharides are glucose what other monosaccharides are absorbed who will tell me yes fructose and and galactose and galactose so it means from GI T lot of glucose is going some photos and some galactose is going the important point which we have to understand the liver cells are master in special function that liver cells can take up the fructose they can take up the galactose and convert them into glucose and release the glucose bath liver cells can take up number one they can take up the glucose and store it and they will release the glucose when blood glucose level is falling number two liver cells can take up the fructose as well as galactose and convert that into glucose so in the end the major fuel may monosaccharide which is reaching to that issue is guru goose is that right even though from JIT some fructose is also coming galactose is coming but because never is present between the Gita and the general circulation and never has a capability liver cells have a capability to convert fructose and galactose into glucose is that right never cells can take up the fructose they can take up the galactose and convert into glucose and they can release that glucose so what we have seen the liver cells can release the stored glucose whenever glucose levels are going down never cells can release stored glucose as well as they can release that glucose which has been made by the conversion of fructose and galactose does that right so it means that most of your tissues right let's suppose we have a cell here this is a cell here most of the tissues in their extracellular environment extrasolar environment means here it is inter yes stiyl fluid and this is blood right now what is the difference of glucose concentration in the blood and glucose concentration in interstitial fluid someone with good knowledge of biochemistry will answer first listen to the question my question is that of course blood is come look OHS is coming into blood from there it should go to interstitial fluid the fluid which is in between the cells and from there the true cause should shift to the south is the right my question is the glucose concentration in the blood and glucose concentration in interstitial fluid what is the difference in that concentration question goes through someone who looks very intelligent all talk yes I think Laura want to say something yes my question is what is the difference in concentration of glucose in the blood and glucose concentration in interstitial fluid where is higher in the blood is higher or an interstitial fluid people who believe that concentration of nações in the blood is higher and concentration of glucose and interstitial fluid is later less they should raise their hands I want to see their beautiful faces okay these are guys and people who believe concentration of glucose is higher in the interstitial fluid they should raise their hands right these people are wrong and now who are these people who raise their hands yes I want to see their these are also wrong the reason being listen carefully the reason being glucose freely shift between these two areas we don't need this is the first lesson we don't need any transporter to shift the glucose from the blood to interstitial fluid is there right right no now you what you are saying please not significantly because as fill cells take up the glucose a little phallus their glucose will immediately shift right because listen carefully that transport of glucose from the blood to interstitial fluid and from the interstitial to blood does not require any transport mechanism glucose can easily diffuse across the capillary membranes that is the point to remember right because we Lucas can easily pass through the capillary membranes so whenever we talk about the glucose concentration in the blood that is what we measure in the blood samples of the patient that is what we Maher right whenever we talk about glucose concentration in the blood actually the same concentration is present in practical for practical purposes same concentration of glucose is present in interstitial fluid now another question what is the difference the glucose concentration in interstitial fluid and glucose concentration inside the cell again glucose concentration extra in extra cellular fluid and glucose concentration in intra cellular fluid right they are usually equal or they are not equal who will tell me yeah that's very important to understand that glucose if someone make like that the glucose can easily jump in and jump out that concept is wrong from here it jumps around like young people but here it cannot jump around why it cannot jump around the reason being that cell membranes are not licky licky to glucose is the right glucose the larger molecule and cell membranes allow smaller molecules to diffuse in and out because glucose is larger molecule so it cannot freely enter into self it means when cells need glucose glucose has to be transferred from the extracellular environment to the intracellular environment through special type of transporters we have to have special mechanisms to get the glucose into the cell those are right now here we come we are going to discuss glucose transport mechanism from extracellular environment to the intracellular environment now there are two types of glucose transport glucose transport across the cell membranes there are two types of mechanism one is facilitated diffusion facilitated diffusion and other is yes other is energy dependent mechanism right that is energy dependent mechanism and usually their transport of glucose is coupled with sodium a you know and some cells glucose stick with the sodium and then sodium dragged the glucose in will talk in detail how so we we said so glucose sodium yes what type of transport core transport as did you have co-education transport right so I have to explain number one how the glucose is going into cell but simple facilitated diffusion and I have to explain to you that in some situations glucose get into cell along with the sodium right right now I will explain first of all facilitated diffusion right what is the mechanism of facilitated diffusion let's suppose this is a cell and it wants to take up the glucose as I told you that glucose cannot pass through the membrane is there right now we need some transport mechanism so what really happens in the south of course you know there there are nucleus and in the nucleus there are genes DNA and some genes they express and make messenger RNA and when that machine your RNA is translated into proteins those proteins will go into and get planted into membranes and those proteins are like this this is a special type of protein and you know how many now this special type of protein which is being expressed right on the membrane this is transmembrane protein because it is through and through this is the right now this protein is very interesting what really happens that outside it has its open mouth and from this mouth it will capture glucose when this protein is expressed right all the time it is like it's just like your mouth you know when you don't have food you keep your mouth open but as soon as you get in you close it this is the right so until there's no glucose here at this mouth remain open as soon as glucose gets stuck here and here what will happen they will close this and open from other side and they will open their mouth from this side and glucose will shift now inside so what is happening that this is a protein which is a transmembrane protein which is through and through the membrane and this protein has a capability to alter its shape when it is not loaded with glucose look at it this protein is like this now it is not loaded with glucose as soon as glucose sit here it open like that is that right now this is the basic way how this glucose transporters work this is the right so this such type of proteins are called glucose transporters and we call it glucose transporters are from glucose and t4 transporters we simply call it glut GL duty blood these going to cause transporters there are up to now they have discovered about 14 different type of glucose transporters the many types of glucose transporters which are expressed in different tissues for different functions this is that right the but first of all you must know the glucose transporters are proteins once they're expressed on the cell membrane they bind the extra cell of glucose and they shift the glucose to intracellular environment and if glucose bind from inside they were shifted to outside also is that right now these glucose transporters that I told you that many types of glucose transporters about 14 different types of glucose transporters this is not right now different types of glucose transporters work in a different way but a very important point which you must know about this glucose transporters is that these glucose transporters are acting as simple do you think they are these glucose transporters are energy to transfer the glucose they are not using energy they are not using any energy right what they are doing they are making the membrane permeable to glucose when membrane has more glucose transporters membrane become more permeable to glucose when membrane has less glucose transporter membrane is less permeable to gurukuls so glucose transporters presence only determines the permeability of the membrane to glucose is the right but how much glucose will pass through this area and depends on the concentration difference of glucose if glucose concentration outside is very high then more glucose will be going in if glucose concentration is very low less glucose will be going and so it means that basically glucose is moving from high concentration to low concentration when any sub molecule is moving from high concentration to low concentration we call it diffusion what we call it process is called diffusion so basically glucoses diffusing from high extracellular concentration to low intracellular concentration but this diffusion is not simple diffusion but this diffusion of glucose is not simple diffusion because if transporters are not there this diffusion will not occur so this glucose diffusion is facilitated by the presence of glucose transporters there right so this type of transport of glucose is called facilitated diffusion why we call it facilitated diffusion first we should know why we call it the fusion because glucose is moving from high concentration to low concentration so it is diffusion but because this diffusion cannot occur simply through the cell membrane so it is not simple diffusion this diffusion has to be facilitated by the presence of glucose transporters am i clear now there are many types of different types of glucose transporters for example there is type 1 glucose transporters some of them glucose transporters you are supposed to know type 1 type 2 3 4 5 & 7 these are the minimum types of glucose transporters which you are supposed to know now type 1 glucose transporter and type 3 glucose transporters they are present on most of the tissues type 1 and type type 1 glucose transporters plus type 3 glucose transporters they are present on most of the tissues most of tissues especially especially they are present on central nervous system and RBC's now these transporters are expressed on many many cells in the body the purpose of these transporter is the basal uptake of glucose basal uptake of glucose is means that when type 1 and type 3 transporters are present over there right they allow the glucose transport into the cell under basil circumstances basil circumstances mean when glucose level is low as I write still glucose is moving to the cell but if glucose level in the blood becomes very high then some cells will need additional transporters some cells will need need additional transporters so basal transport of that glucose transporter one glucose transporter 3 and out of them specially RBC's and brain right they are having much of these transporters and these transporters are responsible ok I tell you something these transporter we say they have high affinity these type 1 and type 3 are having high affinity when I say they have high affinity it means these transporter bind loosely with glucose or tightly with glucose they bind strongly with glucose it means they can transport the glucose because they bind with the glucose powerfully it means they can capture the glucose and transport the glucose even when blood glucose level that low is the right when blood glucose level that low these type 1 and type 3 equal to cause transporters are working this is that right so now we come to some other type of transporters let's suppose we talk about type 4 type 4 transporters type 4 glucose transporters are mainly expressed on the skeletal muscles and on adipose tissue right skeletal muscles and what are these cells loaded with the fat droplets adipose cells they have special their cell they have special type of additional glucose transporters and these additional glucose transporters are their concentration on the membrane is regulated by the importance of some school tell me insulin you know when you your glucose level is going up then beta cells of the pancreas will release insulin insulin will come and bind with cells of the muscles and bind with adipocytes and lead to expression are increase the expression of guru cause transporter for so that more glucose should be transferred to the muscle cells as well as to the adipose cells let me tell you how it happens let's suppose this is a cell and normally type 1 and type 3 transporters are there and they take only very basal level of glucose n but if glucose level in the blood whenever glucose level in the blood become very high what really happens insulin level also goes hi so insulin also goes high insulin is released by the beta cells of the pancreas in response to increasing level of glucose this is the right so that insulin helped the cells to deal with the extra mount of glucose now what insulin is doing and saline has its own receptors this is the receptor of insulin right when insulin binds here when insulin will bind here with the receptor what happens this receptor will give intracellular signals some of these signals insulin stimulated to the scepter and these receptor give intracellular signals some of these signals go to special type of vesicles is the intracellular membrane-bound vesicles and in the wall of these vesicles they are special proteins and what are these proteins yes who will tell me insulin goes to adipocytes and to the muscle cells insulin binds with its receptors and it gives signal inside the cell and once insulin signal come here the result is that that these will flow towards the membrane and this membrane let's suppose this transporter has come here this transporter is this membrane vesicle is here this part of the membrane and this part of the membrane they fuse with each other and what are these proteins you are not telling me these are glucose transporter 4 so what really happens that fat cells and muscle cells have stores of transporters they have stores of transporters in the vesicular membranes and these vesicles are initially present within the cell when insulin stimulates the receptor receptor give the signal and these vesicles start moving towards the membrane then what really happens cell membrane and membrane fuels with each other when the fuse with each other the result will be that you will find this vesicle is fused with the membrane and now vesicular membrane which is loaded with transporter this vesicular membrane become the part of that yes cell membrane and then you find that expression of yes glucose transporter Type four on the cell membrane surfaces increased this is what one of the function of insulin insulin has many functions again it's worth repeating that when in your blood blood glue when in your blood glucose level is going up if your pancreas is normally function beta cells of the pancreas will release insulin and this insulin will come to the skeletal muscle cells as well as to the adipocytes and insulin will bind with these cells here and insulin will give through its receptor insulin will give intracellular signals some of the intracellular signals will activate certain proteins and those protein will pull the vesicles loaded with glucose transporter for and those proteins will drag drag these vehicle towards the cell membrane and eventually vesicular membrane and cell membranes fuse with each other and in this way glucose transporters which were previously present in vesicular membrane under the influence of insulin now they are present in cell membrane and of course permeability of the cell to the glucose is increased so glucose will now more readily go into these cells does the right so we can say that glucose glucose transporter type 4 are your expression in the membrane is insulin dependent but these others are not insulin dependent my no problem right so we were talking about type four yes you have a question yeah Ince look in soon Lily will come it is just like that look just a minute insulin is the hormone all of you know right the hormone is released by the beta cells of the pancreas when blood glucose level is high when insulin come to the blood right it will bind with those cells insulin will bind with those cells which cells are expressing de which cells are expressing the receptors for insulin this is right insulin is a very large molecule it cannot go into cell so insulin will just bind with the receptor and trigger the ballot it will give intracellular signals and this signal to do many things when I will teach you in saline I will tell you one of the function is this signals will transport the vesicles loaded with glucose transporter for to the cell surface and what will happen the glucose uptake by these cells will be increased there's a question neurons brain cells neurons use lot of glucose zero so should the neurons have in what is this type for glucose transporters or not why they should not have again my question is that the neurons really need lot of glucose to further energy they produce lot of ATP and those ATP's in the neurons are specially used to run their sodium potassium ATPase --is right their special cell membrane transporters present in neurons now do you think neurons should have glucose transporters type 4 which are dependent on insulin or not yes they should not have because neurons are so important to us that glucose transport to the neurons should not be dependent on insulin is that right the glucose transport so neurons should have what type of transport are not they should have very high concentration of 1 & 3 1 & 3 so in some books that is why it is written that 1 & 3 are present on neurons but actually 1 & 3 are present in most of the tissue but these transporters are very high concentration on neurons so that this is very important organ brain for most of us is very important is that right so central nervous system should keep on getting the supply of glucose under all circumstances right yeah at the basal rate actually what happens if neuron is metabolically more active it will tjuta lies the glucose more so more glucose will go in because transfer of glucose through that transporter 1 and transporter 3 depends on the concentration difference of glucose outside and inside if neuron become more metabolically active it will use the glucose more inside glucose level will become less and more glucose will chef then does the right but muscles and what is this adipose cells they can store glucose muscles can synthesize from glucose glycogen and store it and fat cells can convert glucose into glycerol which can be utilized in formation of triglycerides that is why when there's excessive extra amount of glucose in our blood insulin is there to specially push this extra glucose into muscle cells and into fat cells am i clear so this is very special point related about glucose transporter number 4 which are dependent on n so why now there is a another transporter that is truly a two-way transporter that there is another glucose transporter and that transporter allows the glucose and to wave movement for example if glucose is high in the blood there is a special type of transporters and if glucose is high in the blood glucose will move in this direction and if glucose is high in the South glucose will move in reverse direction these are two way transporters this two way transporter should be called transporter number one two three four five or seven use your brains some glucose must be going there I'm sure there are two where transporters out of these types which are to where transporters use your brains of course to two-way transporters our glucose transporters type 2 it's a difficult to remember but so easy I don't know why people memorize that that some glucose transporters are two-way transporters so they are fortunately labeled as glucose transporter type 2 for two-way is that right not difficult now there's a real question and you have to use your higher layers of your neurons which type of tissues or cells should have should have glucose transporters - just a minute let me make my question clear I'm asking you a question that out of my all body tissues which tissues and cells must have glucose transporters type - yes please yes chant liver while liver cells yes you said it you are going to tell me why excellent so Patrick knows that liver is very important in one function as you know between the GI T and between the general circulation what is their they are liver cells right so glucose from the GI T and this is general circulation now as we discussed previously the liver cells when glucose concentration is high the more glucose is coming from glucose should go into liver cells and when no glucose coming from GI tea and tissue that we used the glucose and glucose level is very low then liver cells you to release glucose so it means liver cells you should me I should have what type of glucose transporters which work to way number two is the right because liver liver cells are very special cells that when glucose level in the blood is high they will take up the glucose and store the cause as glycogen and when blood level of glucose is less liver cells can break down the glycogen back into glucose and release the glucose even liver cells can synthesize glucose new glucose that process is called gluconeogenesis let me explain it let's suppose here the liver cell when blood glucose level is high glucose will enter into this cell and this cell will make the polymer of glucose and this polymers of glucose are called this is called glycogen so liver cells can take up the glucose and convert into glycogen this process is called glyco Jena dyco genesis formation of glycogen this is one function of the liver and blood glucose level is high it will take the koukos and make the polymers of glucose store the glucose this is that right and when glucose level in the blood is less then they will break down the glucose and bring it back to blood so this process in which glycogen is broken glycogen is broken this process is called glyco Geno lysis so actually there is a transporter here this is glucose transporter to when blood glucose level is high glucose is going to process glucose is going like this and when blood glucose level drop glucose is going from here to out so glucose transporters which are type 2 they should be present in which cells liver cells which is our glucose bank that when glucose is more to deposit glucose there and when we are deficient in glucose we get the glucose from there this process in which glycogen is broken down into glucose is called glyco Geno light says don't call it glycolysis that is not glycolysis glycolysis mean break down glucose into pyruvic acid that is my Conesus this is not break down glucose this is breakdown of glycogen and back into glucose and glucose coming out ok there is another process which is called gluco neo Genesis and by this process liver cells can also produce glucose and glucose will come out it means that when job blood glucose level drop liver will donate you glucose from where glucose bring from where the liver cells bring glucose for you number one a breakdown of glycogen the process is called glycogenolysis then they can make additional glucose from another process called gluconeogenesis what is gluconeogenesis yes dr. Aafia what is gluconeogenesis anyone from here have you heard the word gluconeogenesis what is the kikuna genesis yeah synthesis of glucose but how it is different from glycogenolysis glycogen right okay someone will make a better definition okay the simplest definition as there are many definitions for awhile we have a simple definition gluco neo the stresses on the neo gluconeogenesis glucose formation from new sources new sources are carbon skeleton of fatty acids and carbon skeletons from amino acids so we can say when fatty acids carbon skeleton can be converted into glucose or when from some amino acids amino acids some carbon skeletons can be converted into glucose we say glucose is being synthesized from new sources this is the right gluco neo Genesis this another simple way to tell what is gluconeogenesis formation of glucose from non carbohydrate sources formation of glucose from non carbohydrate sources that's a simple that is gluconeogenesis now the point which I wanted to tell you that all organs the all organs which can do gluconeogenesis must have to weigh transporters so they should have glucose transporter to one organ which is involved in gluconeogenesis is liver any other organ you know which can synthesize the glucose from noon on carbohydrate sources I'm about to be impressed by someone again listen we were talking about glucose transporters but we are trying to make some sense right senses that type to transporter should be present in those tissues specially in which glucose need to be transported in both direction right for example one is the liver what is the other organ in which gluconeogenesis is possible because the second organ can do gluconeogenesis then it can it should also be able to pass the glucose from that organ cells to the blood yes no I already posted break down the lipids triglycerides into fatty acids right and then fatty acid come out so that is classically lipolysis any other tissue which is more actively involved in gluconeogenesis before you tell me something very unusual it is good it is kidney proximal convoluted tubule ourselves or just remember at this right now that kidneys can also do a small degree of gluconeogenesis is the right so liver and kidneys both have glucose transporters type 2 is that right then there is another cell in the body there's another cell in the another tissue in the body in which cells should have glucose transporters in two ways those cells don't produce glucose but they want to have to a guru goes why because suppose that this is that cell I will not tell you the name of the cells you will get these cells should have kind to glucose transporters so that whenever glucose in the blood is high it should immediately go into that cell and if blood glucose level goes down glucose should come out and this cell love loves to keep its glucose concentration equal to extra cellular concentration the seller is very very sensitive to glucose level what this cell is doing whenever glucose level is going up progressively koukos level in the cell is also going up whenever glucose level in the extracellular environment is going down glucose level in this cell should also go in parallel down again there is a very special class of cells in the body and you know them I'm very sure and those cells love to keep intracellular level of glucose absolutely same as extra cellular level of glucose right for that that is why those cells have what type of transporters glucose transporters - and in glucose whenever is going up and the cell dog hood goes up and if glucose on that blood is going down in the cell will it will also go down who is going to tell me the name of these cells why these cells are so desperate to really keep their level of glucose equal to the blood glucose Patrick okay Gary Carlos yes Shawn know anyone okay you tell me one thing which cells in the body attention plays which cells in the body want to be extremely sensitive to the presence of glucose these are beta cells of pancreas because these cells have to release insulin in a very measured way so these cells should be very very sensitive that what is the level of glucose outside so they these cells should taste taste the glucose and then release insulin so they should all that time sense the glucose of course if these cells beta cells of the pancreas if they are not permeable to glucose can they know when to release insulin and when not to release insulin that is so simple so beta cells of pancreas they are look if I say that you should be sensitive for example you are the insulin role either let's suppose come here I he'll just come here let's suppose he's our beta cell of pancreas right this oh my god this beta cell of pancreas right the main function of this is to sense the glucose and release the insulin so initially a glucose has to go inside the cell and then intracellular mechanism determine the level of glucose in the blood and according to that they release insulin how exactly molecular mechanism operate we'll discuss in insulin so beta cells of the pancreas beta cells of the pancreas are very very sensitive to the that glucose level is that right for that purpose they should be freely permeable to blood glucose and only one transporter allows the cells to be freely permeable to glucose that is we type to transporter because let's suppose glucose level in the blood goes high lot of glucose goes in and it starts secreting insulin insulin helped in utilization of glucose and now blood level of glucose goes down the glucose which was previously in that should come out so that cell should know what is the exact level of glucose in that cellar environment so how the beta cells of pancreas know the extracellular level of glucose answerís beta cells of the pancreas are always equalizing that internal glucose concentration with axis a low glucose concentration through which pathways which glucose transporters Kaito so if I asked you there what are the glucose transporters what are the tissues we should have to wave glucose transporters number one those tissue which are which want to release the glucose in emergency like liver and kidney which are involved in gluco neo Genesis that an emergency situation when your blood glucose level goes up liver start doing gluconeogenesis kidneys start doing gluconeogenesis of course they want to release this glucose into blood so those two tissues plus the third tissue is which one vita cells of the pancreas so we know type 1 and type 3 which are present in most tissues especially in RBC's and brain type 2 are in the liver kidney and and pancreas beta cells of pancreas type 4 are insulin dependent glucose transporters they are specifically present in those tissues which want to store glucose right and glucose storages specially in muscle glucose can be going to muscles and transferred into glycogen and second is a deeper side now únicos transporter five únicos transporters five who will tell me what a special thing about glucose transporters five first thing is they are not glucose transporters the fructose transporters they're fructose transporters so glucose transporter five is primarily a fructose transporter right now which are the tissues which have to transfer transport fructose number one should be GA T cells yes to intestinal cells because in the GI T you know from the digestion of carbohydrate you Lucas is produced fructose is produced and galactose is produced so of course these are the mucosal cells from here glucose should go into blood fructose has also and galactose also need to be so there are special fructose transporters which can take fructose from the JT lumen to the south and there is one more tissue fructose is more sweet or glucose is more sweet fructose is more sweet or glucose is more sweet fructose or sweet that is the right answer right so number one in the GI t there must be type v glucose transporters which should help in transport of fructose fructose is very sweet and there is some organ in your body which loves the sweet things especially that loves fructose and that organ has cells which have transporter files because that organ cells love sweet fructose so which organ is present in your body Patrick which love sweets ends really really whenever now he thinks he's all whole bodies like that organ and love the sweet thing this now okay first Patrick is saying my question was that which organ in your body loves to use fructose and needs glucose transporter five right I asked the question to all of you Patrick was very ready to say his whole body like to have fructose transporters sweet things right not lever something really which love the sweet things you don't have a concept of sweet things I think who should be able to tell Robert should be able to tell something some organ in your body I'm sure your pair of those organs please tell me testes testes cells love to run their metabolism of fructose yeah they love the sweet fructose and I don't know Patrick was saying I'm my mom all like that I don't know right but anyway we should not concentrate on Patrick statement all right so let's come back and I don't think of Patrick a lot right so testes testes love to use fructose you get worried why why I will tell you later on alright so right now you just believe my testes love the sweet things including fructose right and fructose should be transported to testicular cells is that right okay I will tell you one more cell which loved fructose at sweet things now you have to be very wise and intelligent to guess that this is one more cell which loves to run its activity on fructose sperm you don't know sperm sperm fructose they love the sweet things you should know by this age right so sperm love the very sweet monosaccharide and run their metabolism on that and that is fructose anyway right now we are not talking about sperm and we are just talking about type 5 glucose transporters which are in fact fructose transporters and number 1 GI T is having fructose after digestion of many polysaccharides so it has to transfer that fructose to wear to the blood so it needs type 5 glucose transporters and one from once from the GI T fructose goes to liver most of fructose is converted into glucose but little fructose still comes into blood and that fructose will be utilized by your testes only right okay so this was something about glucose transporters type 7 type 7 transporter okay before you tell me very funny things right type 7 glucose just a minute type types 7 glucose transporters are present in endoplasmic reticulum endoplasmic reticulum is network of tubules within the cells and these network of tubules have glucose transporter 7 actually endoplasmic reticulum is involved in gluconeogenesis endoplasmic reticulum is a network of tubules in the cells right when we say that liver cell can do gluconeogenesis and we say that in the kidney also some cells can do gluconeogenesis the site of gluconeogenesis is endoplasmic reticulum so they should have some transporter for glucose right and they are having a very special type of glucose transporter which is called glucose transporter 7 yes please you have a question no so muth is specially interested in gluconeogenesis a rough endoplasmic reticulum is more concerned with protein synthesis because rough endoplasmic reticulum has ribosomes on it which are the protein synthesizing organelle as right let's have a break now

Channel: Dr. Najeeb Lectures

Views: 221,840

Rating: 4.8803377 out of 5

Keywords: glycolysis, dr najeeb, dr najeeb lectures, medical videos, medical lectures, usmle, usmle step 1, biochemistry, endocrinology, physiology, armando hasudungan, biology, metabolism, cellular respiration, atp

Id: Y6z1FRTbV3Q

Length: 60min 17sec (3617 seconds)

Published: Sun Sep 16 2018