all right nine so we just finished up talking about how the electron transport chain is utilizing the nadh is from the kreb cycle how it's utilizing the nadh is from the transition step and integrating that into pushing protons out into the actual intermembrane space now we have to discuss how these nadhs specifically from glycolysis are actually being incorporated into this process also so let's go ahead and get started on that so if we look here we're going to have nadhs right so let's say here I have my nadh here's my nadh that I generated from
that stuff what's going to happen is this nadh is actually going to be converted into n a d positive but how is that how is this happening oh let me tell you so if you guys remember you're going to have a molecule kind of in this area here and his name name is actually going to be specifically oxol acetate but from now one we're just going to you're going to see it as OAA okay just so that you guys know I'm going to say oxyacetate but it's going to be written as OA because because I'm
kind of lazy so o AA is going to react with these nadhs when it reacts with these nadh's it's going to get converted into malate okay it's going to get converted into Mali so there's going to be some oxyacetate out here in the cytool and it's going to get converted into malate now I'll explain how this OA is actually coming out but what enzyme is catalyzing this if you guys remember from the kreb cycle it's actually called malate dehydrogenase so malate dehydrogenase was taking the nadh's and dropping it onto the oxy acetate to form n
positive and malate now why did I have to do that why can I just like you know I use this why why did I have to do this specifically OAA isn't able to get transported across the membrane but malate can and we'll see why so now what we're going to do is we're going to take this malate and we're going to see exactly how it's working over here okay so now let's say I take my malate right that malate that's coming over here it's actually G to get pushed in so there's a specific transporter for
the malate so here's a transporter for the malate once the malate is in the mitochondrial Matrix you know what's going to happen with this guy look what's going to happen with this guy it's really cool this malate is going to come over here it's going to come right over here when it comes over here something really really interesting is going to happen so let's see here I have malate when malet comes over to this area there's actually going to be a specific molecule in this area okay so now look what happens malate is actually going
to come over here and it's going to be acted on by a specific molecule in this area you know how when you have malate and you want to convert malet back into OA so that you can get drop off those hydride ions there's a specific enzyme a specific enzyme that pulls those electrons off of the malate and transfers it onto someone else okay so what happens is is I'm going to take this NAD positive in the vicinity and convert it into n a DH right I'm going to take those electrons off of the malate rip
it off of the malet and convert it into nadh when I do that this nadh is that nadh so then look what that nadh can do over here this nadh can actually be involved in this step right there so specifically what's happening that nadh is generated from this step from going from malate right and I'm going to rip off some of those electrons that I got from this nadh out here this is going to get reconverted back into oxal acetate okay now this oxaloacetate is very interesting because what's he going to do now because I
generated oxaloacetate how's this oxal acetate going to get back out okay let's come back over here what happens is let's say here's your oxaloacetate your o a a oxaloacetate is going to combine with a specific molecule it's going to combine with a molecule referred to as glutamate which is an amino acid right when these two molecules interact with one another look what happens the glutamate is going to specifically transfer an amine group onto the OAA when it transfers it onto the OAA the OAA is turn into aspartate which is a specific amino acid that aspartate
is going to move out through this shuttle this asparta gets spit out into the cytoplasm and then you generate from this part you also generate what does the glutamate turn into well you know OA transfers an oxygen onto glutamate and converts them into Alpha keto glutarate now what happens this is Spar is super cool cuz remember I told you we got to figure out how that OA is coming into play look what this guy's doing this aspartate is coming over here and it's going to combine with something else really cool so let's say here's our
aspartate this aspartate is going to react with another molecule out in this vicinity you know what that molecule is called it's called Alpha keto glut8 this is one of the actual components of the KB cycle or from that transamination reaction Alpha ketoglutarate is going to react with the aspartate so aspartate is going to react and guess what you're going to get out of this reaction aspartate is going to transfer his amine group off onto Alpha ketoglutarate and that'll regenerate your glutamate who will also get pumped back in the aspartate is going to get reconverted back
into oxaloacetate where does that oxaloacetate go back into this reaction to keep pulling and plucking those hydride ions off of the nadh to convert him into NAD positive and take these electrons and get them in to be involved in the electron transport chain so again let's explain what's happening one more time so what is happening nadhs can't get across the actual mitochondrial membrane so what do they have to do they have to disguise themselves in a different way so what they do is they drop electrons off onto oxaloacetate through the Mal dehydrogen enzyme converting it
into malate malate can cross the mitochondrial membrane how malate comes over here and it passes through as the aspartate is coming out that malate is then doing what the malate is being acted on by a specific enzyme you know there's an enzyme here that's converting the malate back into oxyacetate and plucking off and getting some nadh's what would that enzyme be called it' be called specifically you already know this enzyme guys this enzyme here is specifically called malate dehydrogenase it's stimulating this step Malay gets converted back into oxaloacetate and at the same time What Happens
the N positives that are in this vicinity are picking up those electrons that are disguised in the Mallet coming from Who coming from this nadh out here then what happens as the Mallet gets its electrons plucked off of him into nadh that nadh is this nadh I'm going to start right actually let me draw a different color so that it's not confusing so nadh and this nadh here so what is actually coming from this step NAD positive to nadh this nadh is that nadh and then look what he can do he can go and drop
those electrons off onto the electron transer chain and it can go and actually help to produce protons out into the inner membrane space so he's also involved that's amazing but how do we get that OA back out what did I tell you that OAA is going to have to combine with something cuz he can't get a across the membrane so what OAA does is it com combines with glutamate glutamate is an amino acid so in other words he has a Amino Terminus and a carboxy Terminus he transfers his amine group onto OAA which converts him
into a new amino acid called aspartate OAA is going to transfer his oxygen group onto the glutamate converting him into Alpha ketoglutarate a sparate can now make it through the actual membrane and so as the malet's coming in aspartates coming out what do you call this they call this the malate aspartate shuttle it's so beautiful all right now as the aspartate comes back out here what's happening with the aspartate because we have to regenerate the OA the aspartate comes back over here and combines with alpha ketoglutarate alpha ketoglutarate then does what accepts the amine group
from the aspartate converting him back into glutamate who will get transported back in then what happens the aspartate when it loses its am group and gains an oxygen from the alpha klutter it gets reconverted back into OA and then OAA is regenerated in this process that is how those nadhs can get in through that mechanism now we have to do another mechanism all right this next mechanism is kind of cool also so what it's utilizing instead of the actual malate it's using a different molecule so let's come over here for a second so let's say
over here I take those nadh's and I want to take these nades and I want to unload them onto somebody who can I unload it onto look at this let's say I have I'll do it in blue here let's say I have here a specific molecule which is called D hydroxy acetone phosphate you guys remember this from glycolysis right it's one of the actual component components of the glycolysis and then what happens is if he gains hydride ions he gets converted into what's called glycerol 3 phosphate now dihydroxy acetone phosphate will get converted into glycerol
3 phosphate whenever the nadh is drop off those electrons or those hydrides right then what happens with the glycerol the glycerol 3 phosphate has a specific channel that he'll bring him into the mitochondrial Matrix and it's doing that because nadh can't get through the actual membrane so glycerol 3 phosphate gets out into this vicinity so now what is the glycerol 3 phosphate going to do let's see you know glycerol 3 phosphate it's actually going to be acted on by another different molecule so look what happens over here you see this guy right here this fadh2
let's say here I bring the glycerol 3 phosphate so I bring the glycerol 3 phosphate into this facin as I do I'm going to take an fad molecule and I'm going to converted into F dh2 now as I convert my glycerol 3 phosphate by having these fads pull and pluck some of those hydrides and electrons ion off of this glycerol 3 phosphate what is it going to convert them back into it's going to convert them back into dihydroxy acetone phosphate so now I'm going to generate this dihydroxy acetone phosphate what did that do for me
I generated fadh2s where do fadh2s go they go right here and they can be utilized in this step but to make it very very specific and so it's not confusing let's do it in another color here so let's show here that this is a different fad going to a fadh2 and again this fadh2 here can be the same fadh2 there which can be utilized in the electron transport chain okay now that we've done that that's another way that we can get those nadh hydrides inside the mitochondria you know there's one more way one more way
and then we're going to go on to the electron transport chain okay so let's say this last mechanism here you know we have what's called uh specifically fatty acids so we'll talk about this when we undergo beta oxidation steps so there's these molecules that we actually have to bring into the mitochondria and in order for them to bring into the mitochondria they have to have what's called a COA on them so let's call these the fatty AAL coas these fatty AAL coas are very very special and what they can do is they can do the
same thing with that fad to fadh2 reaction so now if I come over here I can do this same thing I'm going to come over here like this and what happens is let's do with the same color here this fad can react on this fatty COA and pull some electrons and hydrides off and convert it into fadh2 you know what that does to this fatty COA you know what this is doing it's oxidizing him it's oxidizing them to make a double bond and so specifically we call the result of this Eno COA okay and this
is going to be done by an enzyme called a AC COA dehydrogenase enzyme okay so this is actually going to be done by a this enzyme here working is called AAL COA dehydrogenase and we'll talk about this whenever we get into fatty acid oxidation and then whenever glycerol 3 phosphate is going into dhap and this fad to fadh2 reaction is occurring this is through a glycerol three phosphate what do you think it is dehydrogenate enzyme and he's also stimulating this step and this is stimulating this step and this is just another way for us to
be able to generate fadh2s where's those fadh2s going to go they're going to be involved in the second component of these fadh2s are these fadh2s and they're going to be pushed into this step here and that can be involved in the electron transfer chain all right so now in this video we've gone over the ways that we can get the nadh is from where from glycolysis if there's if there's aerobic conditions because here's the key thing if you guys remember this NAD is only dropping these electrons off onto the electron transport chain if there's oxygen
you guys remember though I told you in glycolysis that if there's no Oxygen the nadhs get unloaded onto pyruvate and converts them into lactic acid so this is only occurring if there is oxygen present and how can you do it three ways one through the Mali aspartate shuttle the other one is through the glycerol 3 phosphate shuttle and this third way is generated Whenever there is beta oxidation so this last step here is in component of beta oxidation and we'll have an individual video on that all right guys so that covers this part in the
next video now we're going to go over specifically how the ATP synthes is generating ATP by oxidative phosphorilation
