Metabolism of carbohydrates

well this is dr. Steven from Team MDS conquer now I'm going to discuss few important topics related to the metabolism of carbohydrates so I'm going to discuss about glycolysis the first important point that you need to add is it's also called as EMP pathway and the definition says glycolysis can be defined as a sequence of reactions converting the glucose or glycogen either into pyruvate or lactate pyruvate will be formed in the case of Arabic reaction in the presence of oxygen and lactate is formed in the case of anaerobic reaction in the absence of oxygen so there are some features that you have to learn about the light Hollis's chandu this reaction takes place in the cells of the body and the enzymes that are really required for this are present in cytosol the second point is glycolysis can occur either in the presence of oxygen or in the absence of oxygen in the presence of oxygen it is called as aerobic reaction and in the absence of oxygen it is called as anaerobic reaction so in the arabic reaction it results in the formation of pyruvate in the anaerobic reaction it results in the form of latter third important point glycolysis is a major pathway for production of ATP in tissues lacking mitochondria regularly mitochondria is the one that is responsible for the production of ATP and it is called as powerhouse of cell but there are few cells where the mitochondria is lagging in which glycolysis is the major pathway by which they generate energy they are Etra sites cornea and the lenses point number four glycolysis is a very essential for brain which depends upon locus further energy so brain the main important mechanism by which it get energy is glycolysis and the next important point to be added the fifth important point is the reversal of glycolysis along with the alternative arrangement of irreversible steps will resulting in the synthesis of glucose that is nothing but gluconeogenesis means glycolysis is nothing but it's a reversal of gluconeogenesis with the arrangement of irreversible steps we'll learn about what are reversible steps and water irreversible steps but if you provide an alteration for reversible steps that like Hollis's process can be reversed and the reverse process of glycolysis is called as like on your genesis i hope you are clear until wrong now we are going to learn about the individual reactions so basically the reactions can be categorized into one that is energy investment means where you how to invest the energy it is also called as priming stays or also called as preparatory stirrers where Energy's utilized invested the second stage is called as splitting phase and the third stage is called as energy generation phase also called as payoff phase so coming to the first one first one is energy investing also called as priming stage also called as preparatory phase so what happens in this ok so there are three major steps which are cuts in this one is the initial product already known already discussed that the initial product for this is glucose so glucose initially is going to convert into glucose 6-phosphate in the presence of either XO kinase or glucokinase engine this already discussed this is an energy investing phase where an energy use used what is the energy ATP is used and the byproduct is adp and in the presence of magnesium ion what is generated glucose 6-phosphate so as already discussed you can see this is an irreversible step okay this is an irreversible step the points to be added about this is so these hexokinase are glucokinase both of these are isomers okay these are isoenzymes so what is the advantage of exogenous like hexokinase is present in all the tissues and it helps in catalyzing or helps in the reaction of hexoses like so kindness helps in the reaction of hexoses the hexoses can be fructose or mannose or anything and the hexa- has low km value the valley is somewhere around 0.1 milli modes and this hexokinase is inhibited by this hexokinase is inhibited by the glucose-6-phosphatase means whenever this glucose-6-phosphatase increases okay the exo kinase activity will be inhibited coming to the second part that is glucokinase so glucokinase is mainly present in the liver whereas hexokinase is present in all the tissues glucokinase mainly acts on glucose whereas hexa kinase can act on all hexoses the km value of glucokinase is more and the valley is 10 millimoles whereas the km value of hexokinase is low km value and the glucokinase is not inhibited by glucose-6-phosphate whereas your hexokinase is inhibited by glucose-6-phosphate so these are the important things that you have to make a note so what is the advantage of having low km value so whenever you have a low km value which means that it has high affinity so as we already discussed that hexa kinase has low km value means which has high affinity means which can utilize the glucose or which can utilize the hexoses even when they are at very low concentration whereas Vanille coming and talking Luco kindness we're talking about gluco kindness glucokinase acts only at higher concentration because it's km values high means preferably gluco kindness will come into action immediately after the meal where the glucose levels will be more but hexokinase can act even at lower levels because of its low km value and high affinity I hope you are clear with the first step which is a very very very very important step why you can ask me why you it's important because the end product of the first step is glucose 6-phosphate it is a center molecule for many metabolic reactions like glycolysis glycol Genesis like on your Genesis pentose phosphate pathway all these cycles or all these pathways they have this as a prime molecule so glucose 6-phosphate has lots of importance so we are done with the first step now moving towards the second step so what happens in the second step glucose 6-phosphate is now going to convert into fructose 6-phosphate means it is changing glucose is changing into fructose and this reaction is mediated by an engine called as phosphor hexa isomers the enzyme is phosphor hexose isomers I hope you're clear this is an isomerase engine okay so we are done but make sure this reaction is a reversible reaction this is a reversible reaction whereas the previous reaction is an irreversible reaction so we are done with the second step so now moving towards the third step where the fronto 6 phosphate is now going to convert it into fructose 1 comma 6 this phosphate in the presence of an enzyme called as phosphor Frato kindness and even in this step there is utilization of energy ok phosphofructokinase utilizes energy where and ATP is used in the presence of magnesium to generate ATP so I hope you are clear with the first three steps the three steps are called as what are they called as they're called as energy investment means you are using some energy what where you are using first Lucas is going to convert it into glucose 6-phosphate by using one ATP molecule in the presence of hexa- or glucagon is make a notable difference between hexokinase and glucokinase then glucose 6-phosphate is going to convert it into fructose 6-phosphate in the presence of an enzyme called s phosphoric so isomerase then fructose 6-phosphate is going to convert it into fructose 1 comma 6 bisphosphate in the presence of phosphofructokinase by utilizing one more ATP and this reaction is irreversible and this reaction is irreversible this reaction is reversible so we are done with the first three steps which are called as energy investment steps where you can see in two steps out of three we are investing energy we are investing the ATP molecule so the second phase is called as splitting phase means you are going to split something what you are going to split this fructose 1 comma 6 bisphosphate is going to break into two parts in the presence of an enzyme called s Alice it's going to break into dye hydroxy acetone phosphate and other molecule is glyceraldehyde-3-phosphate so factors 1 comma 6 phosphate is going to split in the presence of split so that is the reason why it is called a split phase it split into two molecules one molecule is dihydroxyacetone phosphate and second molecule is Disraeli had 3 phosphate in the presence of a yellow Center so this is called as splitting phase clear now what is going to happen now now dihydroxy dihydroxyacetone is going to convert into it's going to convert into glyceraldehyde-3-phosphate in the presence of fast for triose isomers so previously we have one molecule of previously we have one molecule of glucose glyceraldehyde 3-phosphate now we have another molecule so now we have two molecules because this even this is going to convert it into so we have two molecules of glyceraldehyde 3-phosphate for now ok so with this we are done with splitting phase also we are done with energy investing phase with 3 reactions we are done with the splitting face with two reactions and the end product of splitting phase is two molecules of glyceraldehyde 3-phosphate from one molecule of glucose we have initially started our journey with one molecule of glucose now the unproductive splitting phases two molecules of glyceraldehyde 3-phosphate so now what's going to happen so we are done with investment we are done with splitting we are done now the end product is energy generation okay so this is how your preparation will be I can just compare these phases with your preparation the first phase is investing phase invest your time invest your hardwork and everything the second phase is splitting and reading divide and divide and revision and the last phase is energy generation means success phase so once you're done with the exam and everything the next half will be the successful so now the phase is energy generation phase so what we are left with we are left with two molecules of glyceraldehyde 3-phosphate okay so what is going to happen so first initially so this glycerol had three phosphate is going to convert into 1 comma 3 it's going to convert into 1 comma 3 this forceful lizard in the presence of an enzyme called as glycerol head 3 phosphate d hydrogenous so in the presence of glyceraldehyde 3-phosphate dehydrogenase 3 glyceraldehyde phosphate is going to convert into 1 comma 3 bisphosphoglycerate in which in which and a b h+ h+ is generated i hope you are clear with this concept okay so we have started our sixth reaction this is a sixth reaction where the glyceraldehyde 3-phosphate dehydrogenase is going to convert is going to help in converting the glyceraldehyde 3-phosphate to 1 comma 3 bisphosphoglycerate and this step is important as it is involved in the production of NADPH plis a high energy compound that is 1 comma 3 bisphosphoglycerate and of course this NADPH passes through electron transportation chain and helps in generation of ATP which will be learned so this is one of the oxidative phosphorylation level next one so this is going to convert into the next level so we are done with this sixth reaction now we are going with the seventh reaction the seventh reaction is nothing but conversion of 1 comma 3 bisphosphoglycerate 2 3-phosphoglycerate in the presence of phosphoglycerate kinase phosphorylates and this is a place where there is generation of until now we have utilize the ADP and this is a phase where ATP is generated and this level is called as substrate level phosphorylation so the very unique properties of this seventh phase the seventh reaction is this is called as substrate level phosphorylation and this is the only kinase enzyme which is reversible generally if you see go back and just have a look about your kindnesses okay this is a first kinase which is an irreversible reaction this is another kinase which is an irreversible reaction and this is the third kinase enzyme but it's a reversible reaction make a node make a node this is the phosphoglycerate kinase is the only kinase which is the reversible reaction and this reaction is a reaction where there is generation of ATP for the first time and this reaction is called as substrate level phosphorylation so right now you have 3 phosphoglycerate in your hand which is going to convert into 2-phosphoglycerate in the presence of an enzyme called as Mutis that is phosphoglycerate mutase then this 2-phosphoglycerate is going to convert into phosphoenol pyruvate in the enzyme called as in Alice okay so this is very important for dentistry because this is an enzyme which is activated or which is sorry which is inhibited by fluoride so when you use fluoride when you act add fluoride so what is going to happen is the florida is going to form complexes with this magnesium and it's going to inhibit or decrease the magnesium levels by which it's going to inhibit the analyze enzyme and by which it's going to decrease the production of ATP for the bacteria by which decreases the battery bacterial count and this is the same reaction or this is the same mechanism by which the exact lucas level values of an a patient can be determined in blood banks okay I hope you're clear about this so we are done so we got phosphoenolpyruvate so far so phenol pirouette is going to convert it into is going to convert into pie revenge where there will be generation of again an ADB okay so the enzyme pyruvate kinase is the one which helps in that catalysis of this and this is again generation of ATP called as substrate level phosphorylation so here we have two substrate level phosphorylation one is this one this is the this is the one substrate level phosphorylation and the second substrate level phosphorylation is this so you have two substrate level phosphorylation by which the pyruvate is generated at the end this pyruvate generation is called as aerobic method there is other method called as in the options of oxygen that is anaerobic where there will be production of lactic hope everything is clear as of now okay the next thing to be added is about how to count how to count the number of ATP that are generated so now I am going to discuss about the recent modification according to the recent modifications I'm going to talk ok there few textbooks or few I am secure book still going with the old method and whatever method I am talking this recent one and it is according to the fifth edition of such an error which is the latest biochemistry book available in the market now so coming to dry colleges so in glycolysis you have a step where you are going to have an ADP that this is the one but what is going to happen as you have two molecules you'll have two of this so you have two and a B H you have two NADH so according to the recent modification one NADH is going to give rise to two point five ATP so two NADH is going to give five ATP hope yours here and the next one you have to substrate level phosphorylation where you are generating the ATP right one is one is this where you have an ATP but we are talking about two molecules because we have two molecules of glyceraldehyde 3-phosphate so we will get two ATP so here five now it's two now it's seven again in the last step you how to more ATP so you have totally nine ATP are generated of which we are just counting the ATP which are generated in the generation phase but during the investment phase we have used 280 C here we have used 1 ATP here we have used 1 ATP here totally we got 9 minus 2 so it is 782 I hope you are very clear about the number of ATP generated during the or the net number of ATP generated nine minus two so the net ATP generated in the dialysis in the arabic is 780 B I hope you are very clear about this and for example when I'd like wallace's occurs from glycogen here the glycolysis occurred from glucose for example if it is occurring from glycogen one more extra ATP is generated why one more extra tip is generated because there is no need of this conversion because there is no need of utilization of the first ATP which is just used to activate Luca 6 phosphate glucose to glucose-6-phosphate so there will be addition of one more ATP thus in anaerobic glycolysis 3 ATP are generated from glycogen that is more advantageous when compared with the loopers I hope you're very clear about this and few more application things that to be added is about the cancer cells and the glycolysis the cancer cells cancer is uncontrolled division of cells right the simple simple basic definition the cancer cells displace and increasing an update of glucose and there will be increasing in activity of glycolysis as the tumor grows rapidly the blood vessels are unable to have adequate oxygen so the tumor grows very rapidly the oxygen levels to the blood will drop down and lead to hypoxia so what is going to happen the aerobic cycle is going to convert it into an aerobic cycle and this hypoxic inducible transforming factor is a factor which is present in these cells will activate and increase the synthesis of the enzymes that are responsible for glycolysis as well as the helps in transportation of glucose however the cancer cells cannot grow and survive without proper vacillation one of the modality of the cancer treatment is to use a drugs that is going to inhibit the vascular supply to the children by which the cancer can be cured so apart from this you can make a note about the irreversible steps in glycolysis we have already learned ok first if you see the first phase that is the energy investment phase there to irreversible one is so one is your kindness HECO kindness or glucokinase who is the first irreversible step and the second one is phosphofructokinase is a second irreversible step and going to the last one that is this is the pyruvate kinase is the third irreversible steps so the easy way to remember all irreversible steps in glycolysis are kinase there are four kinase out of which one is a reversible kinase we have learned that pgk is a reversible kinase you can exclude that and rest all are irreversible steps and the basic difference between the glycolysis and gluconeogenesis is just the irreversible steps so you need a means it's going to be reversal reversing it's going to be the reversal so you need to give an additional and James for all the irreversible steps means all the kinda all the three irreversible steps you need to have an alternative so that with that alternate the entire process can be reversed so for example if you if you are planning to go back pyruvate to this one this is a single directional reaction so you need an extra and gem for it and from here to here is it is a reversible it will go back here to here is a reversible it will go back here to here this is the only kindness which is a reversal it will go back this this will go back this is the reversible reaction it will go back it will go back here we need an exchanger because it is an irreversible reaction it will go back because it's a reversible reaction it will not go we need provide an extra cell so that's just an alternation of the irreversible reactions will make the cycle reverse and that reverse cycle is called as gluco neo Genesis Dan for now we'll be coming with few more videos to help you out the only thing that we can follow now is the simple principle try to be positive learn as much as you can okay so biochemistry is something called as dry topic but if you take the rough analysis of need exam or any other exam into consideration biochemistry carry half of the weight is of a regular subject means it's going to carry seven months so these are suckers are going to carry 14 similar to that of aims clinicals will carry more marks and coming to comparison with the clinical biochemistry is going to carry less than 50 percentage of marks compared to any other set for example if you're taking Arthas is subject so if you just compare the matrix of ortho to that of the biochemistry either in the aims or in the need biochemistry is going to carry less than 50 percentage of marks when compared with ortho so don't get panic the only suggestion what I can give you this just try to be the best whatever it is whether it's biochemistry or ortho try to be the best learn as much as you can try to be positive okay don't divide or analyze the subjects basing upon their weight is but now you are in a face what face already discussed you are in an mg investing phase in must as much as time as possible as much as energy as possible as much as hard work as possible then you will have a great return similarly like your glycolysis where your energy generation phase will be there we're going to generate something great with whatever you are investing now thank you for now signing off dr. shreek on from team MDS