Metabolism | Glycolysis

our ninja nerds in this video we're going to talk about glycolysis so in short just a little definition about glycolysis if they're going to oxidize a molecule called glucose so you know glucose is a six carbon molecule it's basically a monosaccharide which is just a fancy word for sugar so glucose is a six carbon molecule and we're getting that from our diet we'll talk about how exactly we're getting it from my diet in the digestive system but for right now we're just going to say that we're bringing glucose into our cells which is again as a six carbon molecule and we're going to oxidize him through various steps about ten steps to eventually convert that into pyruvate at least two pyruvates which is to three carbon molecules but the question is how can we get this glucose this six carbon molecule into this cell how do we do that because you know glucose so again what is this molecule right here guys this molecule right here specifically called glucose let's actually write in red make it nice and curly again this is called glucose so glucose is our six carbon molecule we're denoting that by these circles that's one two three four five six thing is though glucose is actually going to be a water soluble solute in other words it can't actually move through the cell membrane by diffusion but passively it has to come through some type of transporter a specialized transporter these specialized transporters are called blood transports so again what is this one called here it's specifically called a glut transporter but let's say that we're having this occur in different organs you know glut transporters or you know glut is glucose transporter they're the ones that are bringing this glucose into the cell but they're not just one direction they're bidirectional so at the same time they can bring glucose from actually what inside of the cells outside of the cell but there's many different types of glut receptors one way that I like to just easily quickly remember all of them it's a helpful mnemonic in my opinion it's up to you guys whether you guys like it here but it goes like this surrounding this be be be ok kids lips are but this doesn't matter ok pink mother-father ok so it's just a little quick way that it helps me to give you basically categorize my glut receptors and it's going to go in a specific order so this is actually going to be for glut1 this is going to be for glut - the pink is going to be for glut 3 and mother and father is going to be for blood for now what does each one of these things mean so BBB the first B I like to remember is blood but specifically what type of blood I mean the red blood cells so on the red blood cells plasma membrane they have a glut one receptor I also like to remember b4 baby but we don't say baby we say the fetus so the fetus is actually going to have glut1 receptors okay and then the last one is the blood-brain barrier so blood-brain barrier you know that's the actual separation between actual vessels and the PIA mater and the neural tissue with the astrocytes around them we'll talk about that more in the neurophysiology but again these are the three easy ones to remember for glut1 BBB blood so there's really red blood cells baby I like that we actually technical as a fetus and the third one is BBB blood brain barrier all right what about the second one so I like to highlight here ki I like to highlight the Li and I like to highlight the PMS right so what does that give me well the ki is going to give me kidney so the kidney has glut two receptors the Li is for the liver and the PS is for the pancreas there is other tissues these aren't all of the Mavi so you can also find the within the gastrointestinal tract there is certain types of glut 2 receptors also but anyway glint 3 pink so I like to remember appiy right there the p4 placenta the in for neuron and another k for kidney so it's not that bad right when you think about it so again what is it going to be it's going to be placenta and then we're going to have neurons are going to have these glut 3 receptors don't get that confused with the actual glut one which is for the blood-brain barrier okay that's different okay because it's going to be where the astrocytes are right between the blood vessels in the astrocytes so don't think it that confuse with the actual neuron cell membrane okay then k is going to be for again the kidney and then the last one mother-father I like to remember M for muscle and F for adipose are fat so again what would this last one be here mother and father is going to be specifically we'll just do these individually mother is for muscle and father is for fat but we should be technical and say adipose okay so the whole purpose of this is just helping you guys to realize that there's many different glut transporters and what they're doing is to bring in glucose from outside of the cell to the inside of the cell but they are bi-directional so they can move it out one more thing I want to mention and want to highlight this one glut4 he's very very particular and the reason why I mentioned all these was particularly for this one and why I want to say this is because glut4 is different from a lot of these other ones these ones are generally insulin independent in other words they don't depend upon the concentration of insulin for their amount this one no glut4 is insulin dependent what does that mean that means when insulin is present he can help to be able to increase the number of glut4 transporters or increase the efficiency of the glut for transporters whereas got one glut two glut three they don't really depend upon the presence of insulin they can function and bring in glucose into the cell out of the cell and they can regulate it based upon the presence of glucose not by the presence of insulin but again that's a quick thing to remember okay so now that we have all of our glut transporters and we know exactly how this glucose is actually getting into the cell now we can move on okay so we bring glucose into the cell through one of these glut transporters depending upon the oregon once we bring it in we have to chain it you know what I mean so because remember what I told you this is actually bi-directional so at the same time glucose could move out to prevent this actual glucose from moving back out we have to put something on it to prevent it from leaving so what we do is we put a special molecule on it look at this so let's say that this is carbon number one two three four five six okay and on the six carbon I have a special thing coming off of it look at that that right there is a phosphate so what did I just put here I put on here a po4 3 negative group does our phosphate group we put a phosphate on the six carbon of glucose so what does want what is it going to be called well this was glucose there's a phosphate on the six carbon of glucose this must be glucose six I'm just going to put pee but you guys would get the point it's four phosphate okay if I abbreviate some of these I'll try to explain them it's just easier to write them down in abbreviation sometimes okay now we got this glucose 6-phosphate the question is how the heck did that happen how did I get this with no phosphate to a phosphate there had to be some enzyme involved yes there was what is the name of that enzyme that's involved this enzyme it depends upon the tissue and we'll talk about it there's two enzymes one is going to be called HEC so kinase okay one is specifically called hexokinase the other one is going to be called glucokinase now we'll keep it the same color the other one is going to be gluco kinase and what is the difference okay hexokinase is actually going to be present within the muscles or other different tissue cells so many different tissue cells but a lot of it is concentrated in the muscles pet technically they call this hexokinase type 2 glucokinase is primarily in the liver so let's actually put that here so hexokinase can be in many different tissues like the muscle it can be a lot of different tissues in the different tissue in the body but the liver is the only one that has glutathione X but they also call it hexokinase for this you guys know okay that was the first step and this is what it's doing it's involved in this step right here these two enzymes depending upon the tissue are involved in the conversion of what glucose into glucose 6-phosphate now the question is where did that phosphate come from I'm glad you guys asked it's coming from taking ATP and converting it into ADP so what happened then I had three phosphates right cuz that's adenosine triphosphate then I went to adenosine diphosphate that means I lost the faucet where to go onto the sixth carbon to glucose who is facilitating that hexokinase and glucokinase next step we're going to go from this molecule now right we're going to go from glucose 6-phosphate to this this number this guy right here but now look at this I'm still going to have the phosphate here okay that phosphate is still present the only thing that's different is all I did is I switched a couple different molecules around a little bit so I switched glucose and I switched its carbonyl form into different types so all I did was I underwent isomerization so in other words glucose 6-phosphate and this other one right here which is called fructose 6-phosphate had the same number of carbons same number of hydrogens same number of oxygens primarily glucose is usually an aldehyde and fructose is usually the form of like a ketone okay so these guys are just interconverting between like an aldehyde the ketone so they're just isomerizing so this step right here step number two because there's a step number one step number two is going to be catalyzed by a phospho hexose isomerase okay so phospho hexyl hexose isomerase because you know hexoses means six carbons so it's a six carbon sugar right here all of this enzyme is doing is converting glucose 6-phosphate into this other guy what does this guy your call this guy here is called fructose 6-phosphate so again what is he called fructose six and I'm just gonna put the P guys four phosphate okay so that was the second step now we're going to go into the third step we'll talk about this third step in great detail in other video when we talk about regulation but in this third step it's a very important step just like this first step is a very very important step and you can tell the difference why can you tell the difference this is a black arrow this is a pink air the pink arrows are reversible steps so what does that mean that means not only can I go from glucose 6-phosphate to fructose 6-phosphate but I could go from fructose 6-phosphate to glucose 6-phosphate but if I wanted to go from fructose 6-phosphate to this next molecule that's possible but I cannot go through that same pathway backwards this step is not reversible by this enzyme that we're going to mention they have to move through another enzyme so this is a irreversible step very regulated okay so the enzyme involved in this step is going to be that of phospho fructose kinase one and like I said I'm just going to abbreviate that pfk once which stands for again phosphofructokinase type one it's involved in this step here okay exactly how is it involved what it's doing is if you notice I'm going to show you something here this was the six carbon this was the one carbon right and then you guys can do the math two three four or five on the six carbon we still have that phosphate nothing has changed there and now it's going to be on the one carbon so now we have a phosphate in the six carbon and we have a phosphate on the number one carbon once this molecule will be called we has a phosphate on the six there's a foster in the first you should be called fructose one comma 6 bisphosphate why don't call biz faucet because you probably heard the term buy phosphate and biz phosphate bisphosphate me that there's carbon spaces between it by phosphate means that they're right next to one another okay so biz phospho means that the actual phosphate phosphate groups are actually separated there a couple carbons away whereby phospho means that they're right next to one of okay but in this case it's biz okay so what is this molecule called fructose 1 6 I'm going to put BP for bids phosphate okay what is the enzyme involved in that step the pfk 1 right what happened I had one phosphate originally on the six carbon then I added another one oh I must have done the same thing that I did in this step here yep so ATP gets involved in this step here and he loses a phosphate gets converted into ADP so I took ATP and converted into ADP okay cool so I lost and I actually used up an ATP in that step now look what happens here I take this fructose 1 6 bisphosphate which is 6 carbons 1 2 3 4 5 6 and I split it in half to 2 3 carbon fragments ok but the phosphate on this carbon right here should be on this carbon here so now let's put a phosphate over here okay and then that phosphate that's going to be over here it should be right there all right cool and again what is this guy right here this is a phosphate and again what does this guy right here called this is a phosphate okay now that we've done that what are these guys called now these ones are a little bit harder than name ok unfortunately I'm going to give you guys a mnemonic at the end will help you a little bit with that but this guy right here is called dye hydroxy acetone phosphate okay so it's a three carbon molecule with a ketone in the middle and a phosphate on that carbon right there okay we could technically called the one carbon but it wouldn't matter cuz on either side you know no matter how you name it nomenclature wise it doesn't matter so dihydroxyacetone phosphate okay there's that guy now the thing is dihydroxyacetone philosophy isn't really utilized in this actual glycolysis pathway he has to be converted into another molecule what's this molecule here called this one right here is different from this guy this one is actually having an aldehyde on one end so we call him glyceraldehyde glycerol - hi three phosphate okay sometimes you might even see it like I'm actually going to denote this one as DHAP dihydroxyacetone phosphate and this one you're probably going to see in other videos as G a 3p glyceraldehyde 3-phosphate okay now here's the thing what enzyme was involved in splitting this puppy okay they call this enzyme involved in this step here right or we can even say if you want to involve in this step here the same enzyme is just cleaving it this same time is called aldolase hey let's actually do it like this instead let's just kind of encase it around this so we'll circle this and this he's involved in both of those steps so he's actually doing what he's cleaving fructose 1 6 bisphosphate into what DHAP and G 83 P now like I told you dihydroxyacetone phosphate doesn't really get it doesn't actually convert into this next glycolytic intermediate he has to be converted into glyceraldehyde 3-phosphate in order for him to be converted into this next intermediate so we have to have an enzyme that is long for this inter conversion between the two or isomerization that enzyme that is involved in this step is called a triose because it's a three carbon molecule saw so I'm going to put P isomerase so it's called a triose phosphate isomerase enzyme and it's involved in the inter conversion between GA 3p and DHAP or DHA p2g a creepy okay primarily with a little bit more of it going towards the GA three-peat depending upon the body's demands though we'll talk about that in other videos now glyceraldehyde 3-phosphate what happens to him he's been going to get converted to this next guy here okay well this guy here has a phosphate on what carbon so let's number this carbon here 1 2 3 ok that means that the phosphate is on the third carbon that's why we named it that well then it should still have a phosphate here I would suppose right let's see okay and as a phosphate here but Oh would you look at that there's another phosphate huh so I added another philosophy okay that's cool now what had to happen then and what would we call this molecule here we would actually call this molecule specifically 1 comma 3 now because the phosphates are actually having a space between them this is biz biz phospho and this actually is just a three carbon glycerate okay so it's called 1 3 bisphosphoglycerate that's this molecule here now there's a special enzyme involved in this step it's a pretty cool enzyme this enzyme is working right here in this step and I'm going to kind of abbreviate him also he is called glyceraldehyde 3-phosphate just like that but d hydrogenase ok this is an important step ok that very important step here what's going to happen is this enzyme this glyph Sarada had 3 phosphate dehydrogenase he's going to do two things he's going to add two things in to this reaction one thing I'm going to do is I'm going to take nad positives in this step ok so I'm going to show it coming off of the I'll show coming off of this reaction here so look I'm going to have NAD+ he's going to react with that glycerol I 3 phosphate in the presence of this enzyme and what he's going to do is he's going to rip off hydrides off of the GA 3 P and when he does he gets converted into in a D H what is hydrides hydride is just a fancy way of saying here's my hydrogen and then this hydrogen it's going to have a proton you know within the center of it and then on what's going to be around it generally has just one electron but in this case a hydride has two electrons so what do we say a hydride is technically we say a hydride is really a proton plus two electrons okay that's what's going to be our high drive and that's what this nad molecule this nad plus is doing it's picking up high driving using converted into NADH here's the case the tricky thing though look at this I want you guys to really really see this this is fructose 1 6 bisphosphate gets converted into DHAP and GA 3p I told you most of this guy's getting shifted over here so how many of him do I really actually have I have two okay I have two of him because I told you most of this is getting shunted over here and then he's running through this reaction twice so if that's happening twice then how many nad s am I actually producing I'm actually producing two I'm having two NADH is being made okay cool that doesn't account for this phosphate this enzyme so tricky he loves to just add in an inorganic phosphate so you see here I'm gonna have an inorganic phosphate I'm just going to throw that into the reaction so GA 3p dehydrogenase is going to just throw a phosphate into the reaction and generate in a ths okay cool so we're good with that step now we're gonna go into the next step now look what happens here you're going to notice something different did I draw a phosphate over here no I do not what does that mean that means that there is I lost a phosphate somewhere but again what would we call this one okay well there's it's going to have a similar name but just get rid of the one so three but no biz it's just a 3 phosphoglycerate that's it so what are going to call this one 3 phospho glycerate okay that's the name of this substrate so again what is this one here called 3-phosphoglycerate now in this step as a special enzyme involved here this enzyme is really cool and what he's doing is he's actually going to help to form let's do this in a nice pink color here I'm going to take a DP and convert it in this step to ATP okay but because this reaction is happening twice how many am I actually producing guys - okay so I'm actually producing two ATP in this step right here okay this enzyme is pretty cool this enzyme right here that's working in this step is called phospho glycerate kinase okay so phosphoglycerate kinase is really really special because what he's doing is what do you what is the definition of a kinase we've talked about it we talked about hacks of kindness and Google kinase but kinase is by definition something that phosphorylates a substrate okay well what is it phosphorylating it's phosphorylating adp where is it getting that philosophy or from the one three BPG it's ripping it off of the one carbon and giving it to ADP to make ATP so that's what he is involved in he is involved in this step here okay good we got our two ATP alright at school okay so now this 3-phosphoglycerate nothing crazy is going to happen in this next reaction it's nothing us not a really special you know reaction nothing significant but look what happened to the philosophy all I did was I switched it mutated it and I switched it from the third carbon to the second car because again we denote this one two three same thing here one two three so I switched it to the second carbon so what would you guys suppose this is going to be this guy's name - phosphoglycerate nothing crazy on this one - Foss though blue serrated okay cool now the enzyme involved in this one's not really that important but we'll mention it anyway just that you guys can have that the enzyme involved in this step converting a 3-phosphoglycerate into the 2-phosphoglycerate it's just called phosphoglycerate mutase so floss though glycerate mutase okay that's that enzyme these familiy mixed up okay cool now the 2-phosphoglycerate is going to go to a kind of an interesting step okay so what are you going to do is this phosphate is on the carbon here right so like let's say I'd 2 here I have a 3 carbon structure just for a second I have a 3 carbon structure and then what I have here is I have the philosophy coming off what I'm going to do is I'm going to switch some structures around and I'm going to convert this into what's called an email and an email is just when you have according to organic chemistry it's a double bond between these carbons with an alcohol coming off like that that's an enol but what I'm going to do is I'm going to put the phosphate on that now okay so I'm going to have it kind of like switched off a little bit so because I have this different kind of structure what I'm now going to have is is I'm going to have this phospho enol and it's a three carbon structure like this last one pyruvate so what is this last molecule called we call this molecule phosphoenolpyruvate so this one here is called phospho enol pyruvate but i don't like that i like that okay it's easier to remember okay but it's you know it's up to you alright so pep and what am i doing all I'm doing is I'm shifting it into a different kind of structure so it's just making it a little bit more modified now okay and then again this is going to be my philosophy so what do I call this boss female pyruvate the enzyme is doing that is trying to convert it into an enol so it's called an email ace so what is the enzyme involved in this reaction here the enzyme involved in this reaction is called a enol ace okay nothing crazy really the more important steps in this process the black lines one that I mentioned as well as this reaction here okay last one I'm taking the phosphoenolpyruvate and look what happens no philosophies that means that I must have formed a teepee again yeah so what I do that means I took two ADP's again reacted them with this phosphoenolpyruvate and made two ATP's what does that mean guys you should automatically arrange to start clicking kinase it's got to be a kinase that's what it is the pyruvate kinase so the enzyme involved in this this step right here for a glycolysis this one here is called pyruvate pyruvate kinase and we're going to have a good discussion on him because he's highly regulated okay and again this step is not reversible you can't go back through this enzyme so pyruvate kinase is doing what he is taking the phosphate from the fossil enol pyruvate and converting it right into pyruvate by transferring that philosophy from the fostering of pyruvate onto the ADP to make ATP but again let's just quickly say something here why am I getting two because there's two glyceraldehyde 3 phosphates there's 2 1 3 bisphosphoglycerate there's 2 3 phosphoglycerates there's 2 2 phosphoglycerates there's 2 caps are following up by rooting and there's going to be 2 of this last guy what does this last guy here called this last guy is called pyruvate which is our 3 carbon molecule now we've been looking to get to by this end point right so now this is our 2 pyruvates ok liking it now one of the thing that we need to mention what's the desk what's the actual fate of pyruvate because he can actually divert into two different pathways one is he can actually come over here and they can get converted into this molecule the other one is he can go over here and get converted into another molecule now since we're only talking about glycolysis we're going to focus on what happened whenever we don't have oxygen and when we do have oxygen so let's say that this pathway is occurring during anaerobic conditions anaerobic conditions meaning no oxygen or very very little oxygen and over here this is going to be aerobic conditions meaning that you have oxygen there's plentiful amounts of it okay in a situation in which we don't have oxygen there's a sit there something bad happens I'm going to show you so you see these NADH is these NADH s are going to go and unload their hydrides onto specific molecules to take it to the electron transport chain and produce ATP but whenever we don't have oxygen these NADH s they have no choice but to unload those hydrides onto somebody their last choice to unload the hydride on is pyruvate and what do they do these NADH s they come over here and they say I can deliver to the electron transport chain because I don't have anyone available to drop it off - and what happens he drops off those hydrides and gets converted into NAD+ so he gets oxidized but the pyruvate gets reduced and gains hydrides and gets converted into a molecule called lactic acid and you know what's happening here you know there's an enzyme a really cool enzyme involved in this step here look at this guy here okay got like six hairs on both sides soldiers are definitely retreating on this guy okay what is this guy doing here this guy right here is involved in this reaction what does this enzyme called it's called lactate dehydrogenase why is this important okay this one is important in the reason why is because lactate dehydrogenase is a reversible enzyme but it's basically converting pyruvate into lactic acid what happens with this lactic acid a couple different things can happen with it it can actually go to the liver and be converted into glucose event eventually or it can go to the liver and be used to make ATP it all depends upon the body's demands but once the other dangerous thing about lactic acid it's very acidic so it's going to actually cause the pH to decrease that was a heck of an arrow there sorry guys this is actually going to cause the pH to decrease it makes the blood more acidic now one other thing is this has a lot of clinical correlation what do I mean so you see that lactate dehydrogenase enzyme if you do a blood plan on blood panel on somebody and you find that they have high lactate dehydrogenase levels what does that mean okay high lactate dehydrogenase I know that he's converting a lot of pyruvate into a lot of lactic acid wait what doesn't happen whenever there's no oxygen or it's very anaerobic yes so what does that mean that means this could be high in certain conditions in which you have maybe some type of mi myocardial infarction maybe you have like a necrotic bowel maybe you have a ski Mia whatever it might be you could be having a lot of different situations where oxygen isn't being delivered to the tissues and because of that what's happening you're not getting oxygen to the tissues in your LD H levels are rising because you have to convert a lot of that pyruvate to lactate acid so you might have some metabolic acidosis also because lactic acid can actually decrease your pH and make it acidic so you could actually might be seeing that in anion gap okay so now let's go ahead and like count up everything that we basically generated from glycolysis so let's kind of tally up just a little bit of notes from this guy's so first off we know that glycolysis is occurring where I don't really tell you where it's occurring in the cell it's actually occurring in the cytoplasm so all the fluid component of the cell that's where it's occurring okay so that's occurring in the cytoplasm of the cell the next thing that we mentioned is what is our starting substrate our starting substrate is glucose okay so we know that what glucose is our I'm going to kind of abbreviate this here it's our starting substrate so I'm gonna put SS starting substrate then we know that this is occurring in the cytoplasm what's our end product so what's the end product will put EP four end product the end product is going to be two pyruvates okay so get two pyruvates out of this that's an end product what some things that I produced which are byproducts of this whole Ridge whole glycolytic process well I actually produced a total of a gross a 480p but out of that since I actually used two of the four of those ATP in the beginning step with the actual glucokinase and also again with the fossil fruit papaya nice I actually used two ATP so really I only net how much two ATP net okay now the next thing is with my nadh s i actually generated a total of two nadh a--'s in this process so i generated two in a DHS and the last thing that i want to mention for this is that this is an anaerobic process right generally it's an anaerobic process if we have no oxygen at generates lactic acid so generally this process is usually anaerobic meaning low or no oxygen and then if that happens then what can you generate you generate lactic acid okay through fermentation processes okay so an inch in short the skinny on is that glycolysis is occurring where it's occurring in the cytoplasm of the cell your starting substrate is glucose your end product is going to be two pyruvate molecules what are you going to have grossing for ATP but you use two out of the four ATP in this process so you only really net two ATP you generated two NADH 'iz and it's an anaerobic process most of the time meaning that there's very little oxygen and if there is very little oxygen those NADH is unloaded onto the pyruvate and converted into lactic acid okay guys so in short that's basically the glycolysis pathway in the next video you guys are going to see something because what we're going to do is we didn't really talk about what happens when there's aerobic conditions anaerobic situations this pyruvate is going to get converted into another molecule with we'll talk about which is a two carbon molecule and this two carbon molecule will have a special thing on it called a co a group and this is called acetyl co X and this is going to be called the transition step and that's what we will talk about in the next video we go over the transition step reaction alright engineers I hope all this made sense I hope you guys enjoyed and there was a lot of information thanks for sticking in there with me if you guys liked it please hit the like button subscribe and put a comment down the comments section iron engineer is until next time

Channel: Ninja Nerd Lectures

Views: 575,847

Rating: 4.9663539 out of 5

Keywords: glycolysis, metabolism

Id: gggC9vctvBQ

Length: 34min 33sec (2073 seconds)

Published: Wed May 31 2017