Electron Transport Chain - Video Tutorials & Practice Problems
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concept
Electron Transport Chain
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7m
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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 E. T. C. And so the electron transport chain, or the E. T. C, is part of the fourth step of aerobic cellular respiration. And really, the electron transport chain, or the E. T. C, consists of mitochondrial inner membrane proteins. And so these air 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 Siris 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 enter membrane 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 E. T. C. 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 and a D. H and F a. D H two which have been generated throughout this process of Arabic cellular respiration. Okay. And so the energy of the electrons from N A. D. H and F A. D. H two is gonna be harnessed in a Siris 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 Grady int by pumping hydrogen ions into the inter membrane 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 like Collis is Peruvian oxidation and the Krebs cycle, we've generated a lot of electron carriers, a lot of N a. D h s and some F A. D. H two s as well. And these electron carriers air gonna take their electrons to the electron transport chain that we have here. And so notice that the n a. D. H is dropping off its electrons here the electron transport chain and becoming an A D plus the empty electron taxicab, if you will, and the F A. D H twos are also dropping off their electrons at the electron transport chain. But just at a different position. And they become f A. D s. And so which you'll notice is that these electrons air getting dropped off at the electron transport chain and they undergo a Siris of redox reactions or oxidation reduction reactions where some proteins are gonna be gaining electrons and they're gonna be losing electrons and others will be gaining them. And they'll continually make their way through the electron transport chain through a Siris of Redox reaction. 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 gonna be used to create ah, hydrogen ion concentration Grady Int, where these hydrogen ions are being continuously pumped into the inter membrane space so that there is a high concentration of hydrogen ions in the inter member in 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 except ER. And so notice up above and our text were defining the final electron except ER. And so the final electron accept her, as its name implies, is the final molecule that's going to accept the electron transport chains, electrons, and so during aerobic cellular respiration. The final electron, except ER, is the molecule oxygen gas, or 02 And so when oxygen gas is serving as the final electron except er, 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 sector, 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 of these electrons that are being dropped off at the electron transport chain are gonna go and make their way through the electron transport chain. And they end up on the final electron except her, which is going to be oxygen gas. And so notice that we have 02 or oxygen gas here, which is the final electron, except her. And then this final electron, except her oxygen gas, is going to react with some hydrogen ions to produce water. And so over here we have hte tuo, which is water. And once again, this is why water is a byproduct of aerobic cellular respiration. And so this year really concludes our lesson on the electron transport chain. But what we're going to learn here is that the electron transport chain is really just part off the fourth step of Arabic cellular respiration. Because really it is step for a and there is a step for B, and that's because the electron transport chain builds the hydrogen ion concentration Grady Int. But then it's Chemie osmosis that utilizes that hydrogen ion concentration radiant. And so the electron transport chain goes hand in hand with Chemie osmosis, which we're going to talk about and another video as we move forward in our course. But for now, this here concludes our introduction to the electron transport chain and how it's used to generate a hydrogen ion concentration Grady int and how it uses Final Electron. Except, er I mean oxygen gas as the final electron, except ER and that oxygen gas will form water. So we'll be able to get some practice applying these concepts as we move forward in our course. So I'll see you all in our next video
2
concept
Remembering the ETC
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4m
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So before we move on and talk about keamy osmosis and this video we're going to share with you a very interesting diagram of this cartoon that can hopefully help you with remembering the electron transport chain or the E. T. C. And so here in this cartoon the electron transport chain is represented as an airport. And so you can see that here this highlighted region represents the inner mitochondrial membrane which is again this airport. And so notice that up above what we have is the outer mitochondrial membrane. And so you can see we're labeling the cytoplasm as this region at the very very top here. And then of course the space in between the inner and outer membranes of the mitochondria is gonna represent the inter membrane space. Which here in this cartoon you can think of as the international airspace. And then of course down below what we have is the matrix of the mitochondria, which is the innermost region of the mitochondria. And so we're calling it here the drop off matrix. And so you might recall that the N A D H and f A D H two electron carriers can be thought of as these electron taxicabs. And so notice that we have these little electron taxicabs down below representing the N A D H and F A D H two. And so notice that these highlighted versions of these taxicabs are in their reduced forms because they have electrons passengers. They carry two electrons. And so notice that this is the full version of the electron taxi cat. And these electron carriers, we know that they can pick up and drop off electrons. And so here these electron carriers are dropping off electrons uh at this international airport which is again representing the electron transport chain. So the electron carriers are dropping off electrons at the electron transport chain. The NADH drop off their electrons at an earlier region than the FADH- two which drop off their electrons at a different region of this airport or different region of the electron transport chain. Now these electron passengers are going to have luggage or um packages that they carry with them. And unfortunately it turns out that the luggage or the packages that these electrons have are going to get turned into lost luggage or lost packages. And so the P and packages can hopefully remind you of the P and protons. And so what this means is that all of these packages or luggage is going to represent protons, which is why we have H plus inside of them. And so we know that there's going to be a build up of protons in the inter membrane space. As these electrons are being dropped off in the electron transport chain. And so these electrons that have been dropped off at these electron transport chain or at this airport are going to need to move through the electron transport chain or move through the airport. And we know that when you get to an airport there are different steps, you have to go through customs and then you have to get through security and then you have to wait and line to get on the actual airplane. And so these electrons are gonna make their way through the electron transport chain to get to this airplane here. And once they're on the airplane we know that they're going to go to their final destination and the final destination represents the final electron except er which we know is going to be the big O. And the big O is Orlando here in our cartoon. And of course the Big O. Or Orlando represents our final electronic sector which we know is oxygen, which is 02. And so Orlando here represents 02 and we know that in Orlando there are many different types of amusement parks and water parks and so you can think of a water park and all of these water slides and we know that once these electrons have gone to their final electron except oxygen, that they are going to react with protons to form water. And so you can think of a water slide here to remind you of that idea. And so we know that a little bit of water will be produced. And so hopefully this little cartoon here can help you with remembering some of the steps and critical steps of the electron transport chain. So that being said, we'll be able to apply some concepts as we move forward and continue to learn more as well. So see you all in our next video.
3
Problem
Problem
In the electron transport chain, the final electron acceptor is:
a) H2O.
b) CO2.
c) H2O.
d) O2.
e) NAD+.
A
H2O.
B
CO2.
C
O2.
D
NAD+.
4
Problem
Problem
Which of the following events takes place in the electron transport chain?
a) The breakdown of glucose into six carbon dioxide molecules.
b) The breakdown of NADH and FADH2 to carbon dioxide.
c) Harnessing energy from high-energy electrons derived from glycolysis, pyruvate oxidation, and the Krebs cycle.
d) Substrate-level phosphorylation.
A
The breakdown of glucose into six carbon dioxide molecules.
B
The breakdown of NADH and FADH2 to carbon dioxide.
C
Harnessing energy from high-energy electrons derived from glycolysis, pyruvate oxidation, and the Krebs cycle.
D
Substrate-level phosphorylation.
5
concept
Electron Transport Chain in Prokaryotes
Video duration:
2m
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in this video, we're going to briefly cover the electron transport chains in pro carry oats. And so pro carry attic electron transport chains are actually really similar to eukaryotic electron transport chains except that they are found in a different location within the cell. And so instead of being found in the inner mitochondrial membrane, like the eukaryotic electron transport chains are the pro periodic electron transport chains are actually found in the cell's plasma membrane. And this is because recall from our previous lesson videos that pro carry attic cells actually do not have mitochondria. They do not have membrane bound organelles. And so down below, we're showing you an example image of the electron transport chain in a gram negative bacteria, e coli. And so notice that the membrane that you see here is not the membrane of the inner mitochondrial membrane. Instead, this is the inner membrane of the gram negative cell. So it's literally the plasma membrane, the cell's membrane, it's not the membrane of an organ L. And the inside of the cell here represents the cell's cytoplasm. Whereas the above the membrane here would represent the peri plasm, basically the space between the cells inner membrane and the peptidoglycan layer that's found on the outside. Uh And so what you'll notice is that the electron transport chain is actually fairly similar. The proteins might be different and there might be some slight differences and things of that nature. But overall the effect is quite similar. Electrons carriers will be dropping off electrons and proteins within the electron transport chain are creating a hydrogen ion gradient. And that hydrogen ion gradient can once again be used to generate a teepee by an uh an A. T. P synthesis, which isn't really being shown in this image. And ultimately oxygen gas can still be the final electronic sector and can react to create water. But ultimately the biggest takeaway here is that the location of the electron transport chain and pro carry outs is different than the location of the electron transport chain in eukaryotes and pro carry attic electron transport chains are found in the cell's plasma membrane, whereas a eukaryotic electron transport chains are going to be found in the mitochondria for cellular respiration. And so this year concludes our brief lesson on this topic here and we'll be able to get some practice applying this as we move forward and learn more as we move forward as well. So I'll see you all in our next video
6
Problem
Problem
TRUE or FALSE:Electron transport in eukaryotes occurs in the inner mitochondrial membrane.
