I earn integers in this video we're going to go into a lot of detail on the electron transport chain okay so where does it lecture on transport chain occur well if you imagine here let's say we took a big big deep look into the mitochondrial this part right here this this line right here this whole thing right here is the outer membrane of the mitochondria so this is the outer membrane of the mitochondria then there is the inner membrane of the mitochondria which is going to have a lot of like nice folding you see how it's like really really folded that folding of the actual mitochondria is called the cristae of the mitochondria okay so what how do you say that it's called the Chris de so again here it is the Chris de of the mitochondria and it's the inner mitochondrial membrane so we going to get the outer membrane of the mitochondria and then you have the inner membrane of the mitochondria which is going to be folded so they call it the crisp a then you have this space you see this space right here from the inner mitochondrial membrane to the outer mitochondrial membrane they call that the inter membrane space then inside of the mitochondrial membrane the inner mitochondrial membrane this is going to be what's called the mitochondrial matrix this is where a lot of the Krebs cycle activity is occurring a lot of stuff that you've seen in a lot of these reactions with the conversion of specifically the pyruvate to acetyl co a and then the Krebs cycle so again one more time this is the outer mitochondrial membrane which is close to the cytosol so it is where the cytosol of the cell would be then you have the inter membrane space then you have this inner mitochondrial membrane which is folded so it actually is called cristae and then you have the inner fluid of the mitochondria which is called the mitochondrial matrix specifically the electron transport chain is occurring on the inner mitochondrial membrane and we're going to talk about each component of that in very great detail so let's go ahead and get started so how does all of this actually occur well if you remember we had to start with the glycolysis so we took glucose which was that six carbon unit oxidized it generated some NADH s and a little bit of ATP to adp net and made it and converted it into two of these suckers right here so two of these puppies what are these three carving units right here this is called pyruvate pyruvate this black marker looks good so glucose 2 2 pyruvate molecules right and this is going to be splitting a six carbon molecule into two three carbon molecules and you're generating these two NADH s which will take them to the electronic transport chain we'll have another part of this video where we'll take the NADH s and show how they get into the actual mitochondria because there's a special mechanism for that okay then that pyruvate if there is oxygen present the pyruvate gets pushed into the actual mitochondrial matrix their specific transporters and then it gets acted on by the pyruvate dehydrogenase enzyme if you guys remember that complex and then I converts it into acetyl co a which is this 2 carbon here so again right here is your pyruvate you guys should know all of this already and then this is going to be your acetyl co a right which was generated from that pyruvate dehydrogenase enzyme what was the significance of that you generated two NADH s from that reaction and then if you remember we're not going to go each step for here because we've already done it you know that you'll go through the Krebs cycle and through specific sequences of the Krebs cycle you generate how many NADH s you generate 2 4 6 nadh s and then also you generate to fadh2 s so this is the significant part here how many fadh2s that i generate - and how many NADH is did I generate total let's show that in one whole go here out of this out of all of this I generated a total of 6 nadh s from the actual krebs cycle that doesn't include the two NADH s from the transition step and the 2 NADH is from glycolysis now these NADH is and what else these fadh2 is that I generated the to fadh2 s here they're going to be very special because they're going to take those high drives if you guys remember they're called hydride ions what's a hydride ion that you guys remember quickly it's just specifically a proton with two electrons right that's all it is a little hydride is it's just the proton with two electrons these guys are carrying that now these two guys are electrons shuttles what they're going to do is they're going to take those electrons and take it to this actual electron transport chain so let's focus in on specifically how NADH is doing at first and then we'll do fadh2 okay so here we're going to take our NADH so we're going to take one NADH and see how it's reacting right here so what happens is you have this NADH this NADH is going to come into this action it's going to react with this first part of the electron transport chain and what's going to happen is it's going to go in and NADH and it's going to come out as nab positive what happened in this reaction that NADH got oxidized into entity positive nearly inside of here there's actually going to be specifically a flavin mononucleotide so here we're going to have this thing called a flavin mononucleotide that flavin mononucleotide is going to pick up those electrons off of the NADH and then it's going to get converted into flavin mononucleotide which is carrying the actual electrons so this is going to be the slave in mononucleotide carrying the electrons and then it can also pass it on to iron sulfur clusters but specifically what's happening at this first step here NADH is getting oxidized to nad positive and then flavin mononucleotide is getting reduced in to leave them on a nucleotide with the electrons and then what happens this flavin mononucleotide will react with this guy over here this guy over here is going to be called coenzyme q so look what we have here I have coenzyme q coenzyme q is going to come and react with that FM and h2 look what happens he's actually going to pick up the electrons from this FMN h2 when he picks up the electrons from an FM n h2 he gets converted into coal enzyme q and specifically they call it h2 okay so again what happened here in this first part NADH dropped off its electrons to the FMN who got convert into FMN h2 which is the reduced form of flavin mononucleotide that flavin mononucleotide he passes the electrons on to coenzyme q which gives you the reduced form of coenzyme q and then he'll take these actual electrons and pass them on to the next step before we do that now let's see how fadh2 is doing this okay because now we get a look at how exactly fadh2 is performing this function okay fadh2 is going to come to this one right here so let's show fadh2 coming up over here fadh2 is going to come on to this actual the specific component of the electron transport chain and what it's going to do is it's going to drop off his electrons okay he's going to drop off his electrons and when he drops off to his electrons what would he come out as he would come out as f a d accid eyes when he gets oxidized who gets reduced if you remember again over here I'm going to have V flavin mononucleotide he's going to pick up those electrons and get converted into flavin mononucleotide which is in the reduced form with the actual electrons then what happens look what else I have over here you know this this guy right here this Q this coenzyme q you know he's a mobile molecule you know it's also not made of protein eat either he's one of the only ones throughout this entire electron transport chain that's not made of protein he is actually mobile along the membrane so he can run ahead and as he runs ahead he gets over here and now look at him coenzyme q right here he's like hey FM NH to give me those electrons I'll take care of them and he gets converted into the reduced form of coenzyme q which is Q h2 okay so what has happened so far with the fadh2 in nadh s nadh dropped his electrons off onto this first complex you know that's what we call it we call this specifically you know we call this first one it's test two names I can either call this complex one or I can call this in a DHD hydrogenase because what did I tell you guys anytime you have nadh being dealt with what do you know is going to be there a dehydrogenase enzyme so there's going to be an NADH dehydrogenase or you can also call this one complex one then where do these electrons go from complex one or the NADH dehydrogenase they get passed on to coenzyme Q and then coenzyme q gets reduced so this is actually going to be specifically what's this molecule called this guy right here is called coenzyme q and sometimes you might even see it written as coenzyme q-10 okay then i just coenzyme q where is he going to pass those electrons we didn't talk about that yet we're almost getting there before we do that let's see what happened with the fadh2 fadh2 dropped his electrons off onto this second complex if you will so what does this guy here call this is actually going to have two names again I can call this one specifically I'm going to call this one succinate dehydrogenase or they can also call it specifically complex two now complex two or succinate dehydrogenase is going to do what it's going to take the fadh2 and convert it into FA D doesn't this enzyme sound familiar do you remember the same time guys it was actually occurring here in the Krebs cycle remember when you were taking suctioning you were converting in a duty Mary what was it doing it was taking F ad and converting it into fadh2 but remember I told you it's not a heavily regulated step so what does that mean it's reversible so this is the enzyme that's actually going to be involved in the Krebs cycle as well as in the electron transport chain now before I move on I want to explain something with respect to complex one or NADH dehydrogenase but I have to do it with a graph so let's say over here I have a graph and on the y-axis it's measuring energy and on the actual x-axis it's like the reaction progress okay let's say I take this first NADH dehydrogenase and he's sitting here at lower energy and I take the electrons from the NADH and I pass it on to him if I pass that on then he's going to go to higher energies who is this one this is complex one or the NADH dehydrogenase enzyme alright it's a complex when this actual enzyme complex one goes to high energy levels it doesn't prefer it it doesn't like to be at high energy levels he doesn't like that no one likes to be at higher energy levels so what he decides to do is decide I don't want these electrons I'm going to pass these electrons on to someone else and when he does that he loses the energy and he goes back down to low energy levels okay when he goes down to low energy levels from passing what casting the electrons away what happens he has a special type of poor so let's say here is a component of this actual enzyme complex look over here it has a poor and on this poor it can do something really special what was NADH again it was consisting of hydride what's a hydride it's a proton and two electrons all we did was pass electrons onto this complex one where'd the protons go these protons are going to get pumped out okay and it's going to get pumped from the actual mitochondrial matrix into the intermembrane space and what allows for this whenever the electrons from complex one is getting passed on to coenzyme q now coenzyme 2q takes these electrons and he'll pass it on to someone else which we haven't talked to yet but what about complex two let's see here I have complex to complex 2 is going to get these electrons from fadh2 he's going to go to high energy levels when he goes to high energy levels he doesn't like it so he passes it on to the other columns i'm Q and it goes back down to low energy levels but look he doesn't have a pour he doesn't have a protein the component that will pump the protons out so no protons are getting pumped out through the actual mitochondrial matrix and then to the end membrane space at complex 2 or succinate dehydrogenase only complex 1 okay now it's time that we explain this next point so this Q h2 that coenzyme q h2 which is in the reduced form what's he going to do he's going to take those electrons and he's going to pass those electrons on to this other coenzyme q here so he's going to pass these electrons onto that coenzyme q and helps to form another qh2 who else is doing that this fadh2 is giving it to FMN who's getting converted into FM NH 2 who's also helping to mak invert coenzyme q into the reduced form of q and coenzyme q and again what is this molecule here cold this right here specifically called co-enzyme q10 right or ubiquinone they even call it ubiquinone now what happens with this ubiquinone well now he's going to take those electrons and pass it on to the next guy this is complex 3 so now we're going to go into the next one which is going to be specifically complex 3 but you know they have another name for complex 3 so this is complex 3 but they also call complex 3 something else they also call complex 3 a weird name it's called coenzyme q cytochrome B Axio reductase okay so again what is the name of this coenzyme q cytochrome B Axio reductase that is its name or you can even call it cytochrome bc1 complex or you can just call complex 3 it's up to you guys all right but anyway what's happening here you have this cytochrome and you know cytochromes are interesting because they're basically kind of like keene groups they have a porphyrin component of them which is like a pigment as well as having some type of usually an atom or mineral or specifically a metal and the center component of it in this case it's iron so let's say I have here I have cytochrome B and I draw here cytochrome B and the cytochrome B specifically has iron here and it can have an iron here now what happens is as this coenzyme q h2 right it's going to pass these electrons onto the cytochrome B when it passes the electrons onto the cytochrome B who is it specifically going to pass it on well you know iron can exist in two states right so let's say that he passes these electrons over here and when he does that this guy gets converted right back into his original state because he's given those electrons away he is going to accept these electrons when he accepts these electrons he's going to get turned into a different oxidation state you know what state he's going to be in here it's going to be plus three if he gains an electron one at a time right would it become plus two so specifically what's happening is that coenzyme q h2 is passing this electron onto at the plus three and Fe plus three is getting converted into Fe plus Q because he's accepting that electron now same thing like before let's say I have this graph here I keep extending my graph if I keep extending my graph now what's this enzyme complex 3 going to be at before it accepts the electrons at low energy but then it accepts that electron and when it accepts those electrons it goes to high energy he doesn't like it what is he going to do he's going to pass the electrons on to the next guy which is going to bring him down into low energy you know what's special about this guy just like complex one he has another channel off the side and off to the side of this guy he's got this little poor you know what this poor is going to be doing it's going to be pumping protons out here into the intermembrane space from the mitochondria majors because you know there's going to be protons which are going to be concentrated in this area right the concentration in here you're going to have a lot of protons in here too usually this concentration in this area is usually around 10 to the negative nine right and specifically this might be a milli molarity right so you're going to have some type of concentration in here and usually before these protons are getting pumped out into this area it's also about 10 to the negative nine milli molarity so usually they're pretty much equal before you start pumping tons of protons out we'll see how it changes but it's pumping these protons out into the actual inter membrane space at what point at complex 3 and at complex 1 or you can also call complex 3 cytochrome Q us specifically coenzyme q cytochrome B Axio reductase then what happens this guy right here is going to pass these electrons on to the next guy okay who is this next guy this guy right here is specifically going to be called cytochrome C since it's called cytochrome C so they call it cytochrome C so what cytochrome C is consisting of a still still the same it's going to have that heme group in it right so here let's say you ever cytochrome C and again it's going to have iron in it and it might even have copper as well incorporate it into it also but again what's happening this iron passes electrons onto this Fe 2 plus there's Fe 2 plus is at high energy States he doesn't want to have those electrons anymore what is he going to do he's going to take and pass those electrons on to this guy so now look what happens these electrons are going to get passed over on to this guy and he's going to get regenerated back into Fe 3 plus when he does that this guy is now going to do what well specifically let's say that we do the same thing let's say that this iron right here reacts with that and picks up those electrons if he picks up those electrons what he bien he should be in the plus 3 state when he accepts those electron see she's now going to the +2 state and again you can have copper as a component of this cytochrome - then what happens then we go on to the last one at the last one we have it called as complex 4 or like always it can also have another name they also call this cytochrome oxidase and you see why they call it oxidase it is a very very important complex okay now same thing it's going to become redundant here and I know this is going to be specifically this cytochrome oxidase is actually consisting of cytochromes but specifically cytochrome a and also a 3 so cytochrome a plus a 3 so it consists of these two cytochromes and this actual enzyme complex and once again this cytochrome a plus a 3 is going to be consisting of iron and what's happening here this iron is in the plus 2 state so if he's at the plus 2 state he's not going to like that he's at high energy status he doesn't want to be at high energy status he's going to take those electrons and pass it on to the next guy it's just like a a game of hot potato right I don't want it Who am I I'm enzyme complex one I'm going to give it to the next guy Cowen's I'm cute coenzyme q doesn't want he gives it to another coenzyme q 2 doesn't wanted he gives it to coenzyme q q gives it to who cytochrome B cytochrome B gives it to cytochrome C and cytochrome C gives it to this actor cytochrome oxidase and it's just a game of hot potato all the way down now when this guy passes his electrons back over here because now look he's going to come from here and he's going to pass these electrons back over to this guy what do you think this guy's going to do same thing he's going to pick and accept those electrons when this iron which is going to be again redundancy plus 3 he goes back into the plus 2 state he accepts those electrons then what happens something very very interesting happens you know in this area I'm going to have specifically I'm going to have oxygen so I'll have oxygen out here so let's say here I have some oxygen and specifically it's the atomic oxygen so if about 1/2 of an oxygen that's just specifically atomic oxygen that 1/2 of an oxygen is going to react with this iron in the +3 state and this iron the plus Tuesday specifically the +2 state 1 so as this iron in the +2 state is going back to the +3 state he's giving his electrons to who he's giving it to this oxygen this oxygen is then going to pick up those electrons from that +2 iron you know what else is going to get combined in there 2 protons so now these 2 protons are going to get combined with the aw 1/2 of an oxygen so you're going to have 1/2 of an oxygen taking up these electrons from the plus 2 iron in the cytochrome a plus a 3 going back to plus 3 he's going to accept those electrons combine with 2 protons and make water it's beautiful so what happened here then I took half of an oxygen to H pluses and I accepted those electrons there's electrons go anywhere else no that means that this oxygen is the final electron acceptor so when hot potato hot potato hot potato and then gave it to oxygen and he just accepted it he's like ok I'll take the potato right so he is going to be the last one of the electron transport chain accepting those electrons so now before we go back over here and review this one more thing happens just like this guy let's come back to this graph this complex 4 is that low energy levels but then what happens when this complex 4 accepts the electrons from this cytochrome C right the +2 iron is giving the electrons to the cytochrome a plus a 3 he's accepting those electrons and going to high energy levels does any molecule prefer high energy levels no so what did he do he gives those electrons to who to the oxygen and then the protons to make water when he passes those electrons away his energy levels go back down that energy is harvested to do what look what happens here here what do you think I have right here into this membrane I have a little channel and guess what I'm going to pump out of this sucker right here I'm going to pump out a proton so I'm going to take a proton and I'm going to pump that proton we're from the intermembrane space into the I'm sorry from the mitochondrial matrix into the intermembrane space so now let's review from beginning to end what's actually happening so where do we start we started at complex one or again NADH dehydrogenase the NADH is dropping the electrons off to this complex one specifically the flavin mononucleotide and they're also just remember I'm going to write it down technically this flavin mononucleotide is passing the electrons before it goes to coenzyme q it's passing it to a lot of iron sulfur cluster proteins it's not significant in this concept just know that it's passing it to a lot of iron sulfur cluster proteins anyway once this NADH passes electrons that goes to any positive and then this FMN gets converted into the reduced form of F in it and technically this F M in a reduced form is going to pass it onto a bunch of iron sulfur cluster proteins which is this get then going to pass those electrons on to who specifically it's going to pass it on to coenzyme q coenzyme q is going to be a mobile specifically what it's a mobile electron transport chain component but it's not made of protein the coenzyme q is going to accept those electrons and get converted into the reduced form of coenzyme q and he'll pass those electrons on to another non reduced form of coenzyme q to make the reduced form of coenzyme q because you get to be able to be mobile it can be throughout this actual inner mitochondrial membrane at the same time that's happening fadh2 is also being converted into fa D he's getting oxidized who's picking up those electrons the flavin mononucleotide and the enzyme component of succinate dehydrogenase and then it's getting converted into the reduced form of flavin mononucleotide okay and this also consists of some different types of iron sulfur cluster proteins but then what happens to this reduced form of flavin mononucleotide the coenzyme q is going to pick up those electrons and get converted to the reduced form of coenzyme q also remember at complex 1 what was happening when this electrons were getting passed over it was pumping a proton out then these electrons from the actual complex to where the suction a dehydrogenase gets compassed on to specifically coenzyme q here also coming from the coenzyme q before this coenzyme q is going to react with q cytochrome b ox co-reductase or you can call it cytochrome bc1 complex or you can just call it complex 3 specifically what's happening here this cytochrome B is consisting of iron and this iron iron components here are going to be accepting the electrons which one iron in the +3 state is going to accept the electrons from the coenzyme q and go into the +2 state then it's going to take those electrons and pass it onto another iron who's going to be in the +3 space so they can go into the +2 state in the component of cytochrome c but when it passes those electrons over to the cytochrome c he goes from hi interviewed low-energy and pumps out a proton from the mitochondrial matrix into the intermembrane space then the cytochrome c is going to do what when it accepts those electrons it goes from the plus 3 iron state to the plus 2 iron state and then again it goes to high energy doesn't want it passes electrons on to cytochrome oxidase or enzyme complex 4 which is consisting of cytochrome a plus a3 then what happens this is also consisting of iron and he accepts those electrons from the cytochrome c and goes from the plus 3 state to the plus 2 state doesn't want those electrons to high-energy what does he do he passes electrons onto oxygen who is the final electron acceptor who will then combine with two protons to make water but when he goes from the plus 2 back to the plus 3 back to low energy levels it creates opens up this pore to push a proton out so again at what points here are we actually pushing the protons out specifically we're pumping a proton out at complex 1 we're not pumping a proton out at complex 2 we're pumping a proton on at complex 3 and we're pumping a proton on at complex 4 and this is dude again to whenever it's from high energy transitioning to lower energy now as all of this is happening what's happened to the proton concentration out here now now we can go and explain to this next part to at least for a second now the proton concentration out here is going to be much higher than the proton concentration in the mitochondrial matrix we're pumping tons of protons out here this proton concentration can go up until about ten to the negative seven milli molar whereas what was it in compared in the mitochondrial nature's it was about 10 to the negative nine million more so now there's actually a two-fold increase in the protons out here in the intermembrane space and this establishes what's called a concentration gradient and we'll talk about that in a second so now what's the problem though we're not done yet and you want to know why we took care of the NADH s from the krebs cycle these six NADH s and we took care of the two NADH s from the transition step and we took care of the 2a fadh2s from the Krebs cycle but what any deej is have we not accounted for yet these suckers right here now we have to figure out because here's the problem any BH can't just cross the mitochondrial membrane it has to have a special obviously complex way to get in and then drop those electrons off that's what we're going to do in the next video so in the next video we're just going to continue along with the electron transport chain but talking specifically about how these NADH s are getting into the mitochondria and doing these functions