In this video, we're going to begin our lesson on the electron transport chain. And so the electron transport chain is commonly abbreviated as just the ETC. And so the electron transport chain or the ETC is part of the 4th step of aerobic cellular respiration. And really the electron transport chain, or the ETC, consists of mitochondrial inner membrane proteins, and so these are going to be proteins that are found in the inner mitochondrial membrane. And so if we take a look at our image down below, notice that these series of proteins that you see embedded in the membrane represents the electron transport chain. And it's important to note that in this image, that we're still looking at the mitochondria. And so this membrane that you see here represents the inner mitochondrial membrane, and this membrane that you see up above represents the outer mitochondrial membrane. And so of course that means that this space that's down below here within the inner mitochondrial membrane is going to be the mitochondrial matrix. And then we have the inner mitochondrial membrane and then the space that's in between the inner and the outer mitochondrial membranes which is basically this space right here. This space represents the intermembrane space. And then of course on the outside of the outer mitochondrial membrane, which is basically this blue space that you see up above here, this represents the outside of the mitochondria, but still inside of the cell. So it's going to be the cytoplasm of the cell. And so really we're looking at the mitochondria here in the electron transport chain.
Now it's important to note that the electron transport chain or the ETC is going to be responsible for harnessing the energy of electrons as its name implies. And these electrons are going to come from the electron carriers NADH and FADH2, which have been generated throughout this, process of aerobic cellular respiration. And so the energy of the electrons from NADH and FADH2 is going to be harnessed in a series of redox reactions or oxidation reduction reactions. And ultimately the energy of the electrons from these redox reactions is going to be used to generate a hydrogen ion concentration gradient by pumping hydrogen ions into the intermembrane space between the inner and outer mitochondrial membranes of the mitochondria. So let's take a look at our image down below to clear some of this up.
So throughout our process of aerobic cellular respiration and glycolysis, pyruvate oxidation, and the Krebs cycle, we've generated a lot of electron carriers. A lot of NADH's and some FADH2s as well. And these electron carriers are going to take their electrons to the electron transport chain that we have here. And so notice that the NADH is dropping off its electrons here at the electron transport chain and becoming NAD+, the empty electron taxi cab if you will. And the FADH2s are also dropping off their electrons at the electron transport chain, but just at a different position and they become FADs. And so, what you'll notice is that these electrons are getting dropped off at the electron transport chain and they undergo a series of redox reactions or oxidation reduction reactions where some proteins are going to be gaining electrons and they're going to be losing electrons and others will be gaining them and they'll continually make their way through the electron transport chain through a series of redox reactions. So the electrons are moving through. They get dropped off, the electrons get dropped off, and then the electrons move their way through the electron transport chain through a series of redox reactions. And the energy from those redox reactions is going to be used to create a hydrogen ion concentration gradient, where these hydrogen ions are being continuously pumped into the intermembrane space, so that there is a high concentration of hydrogen ions in the intermembrane space.
Now notice here that the electrons that are being dropped off and moving through the electron transport chain, those electrons end up on what's known as the final electron acceptor. And so notice up above in our text we're defining the final electron acceptor. And so the final electron acceptor as its name implies is the final molecule that's going to accept the electron transport chain's electrons. And so during aerobic molecule oxygen gas or O2. And so when oxygen gas is serving as the final electron acceptor during aerobic cellular respiration, it's ultimately going to interact with some hydrogen ions to form water. And water is going to be a byproduct of aerobic cellular respiration. And when you go back and look at the overall chemical equation of aerobic cellular respiration you'll see that water is going to be a byproduct and that's because oxygen is acting as the final electronic acceptor reacting with hydrogen ions to form water. And so let's take a look at our image down below to clear some of this up, and once again notice that all these electrons that are being dropped off at the electron transport chain are going to go and make their way through the electron transport chain, and they end up on the final electron acceptor, which is going to be oxygen gas. And so notice that we have O2 or oxygen gas here, which is the final electron acceptor. And then this final electron acceptor, oxygen gas is going to react with some hydrogen ions to produce water. And so over here we have H2O, which is water. And once again, this is why water is a byproduct of aerobic cellular respiration.
And so this here really concludes our lesson on the electron transp