Redox Reactions - Video Tutorials & Practice Problems
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1
concept
Redox Reactions
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4m
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in this video, we're going to introduce Redox reactions, and so Redox is really just short for oxidation reduction. And so you can see that the R E D n Redox is for the ar e d n reduction, and the X and redox is for the O X and oxidation. And so oxidation reduction and Redox reactions are referring to the same exact thing, and they refer to reactions that involve the transfer of electrons between molecules. And so this symbol here is the symbol for electrons, which is an E with a negative sign. And that's because we're called from our previous lesson videos that electrons are negatively charged and so within oxidation reduction, you can see the two words oxidation and reduction, of course. And so we're gonna define what each of these words is referring to. And so oxidation is the process of losing one or mawr negatively charged electrons, whereas the process of reduction is the process of gaining one orm or negatively charged electrons. And so if something is gaining negatively charged electrons, then that means that it's overall charge is going to be reduced because it's gaining negatives. And so that is why reduction is the process of gaining negatively charged electrons now. It's also really important to note is that oxidation and reduction reactions always occur simultaneously, which means that they always occur at the same exact time. And that's because if something is losing electrons, then something else must be gaining those electrons. And so this is why oxidation reduction reactions always go hand in hand with each other. So let's take a look at our example down below at these redox reactions or oxidation reduction reactions. And really, when it comes to Redox reactions, all you really need to remember is Leo The lion goes girl. And that's because if you can remember that Leo the lion goes girl, then you'll be able to remember that anything that loses electrons is going to be oxidized. And oxidation just refers to anything that loses electrons, whereas the ger here refers to gaining electrons is reduction, and so anything that gains electrons is going to be reduced. And that means it's charge is gonna be reduced because it's gaining negatively charged electrons. And so just by remembering Leo, the lion goes Ger, then you'll be able to remember that oxidation is losing electrons and reduction is gaining electrons. And so now below, we have a little image of Leo here on. You can see that, Leo the lion is going, girl. And so again, by remembering this, you should be set on your problems for Redox reactions. Now, over here on the right hand side, what we have is an image to show you that oxidation and reduction reactions always go hand in hand. And so you can see here that we have a person that has some electrons in their hands right here. And this little blue circle with the negative charge in it is representing our electron. And so what you can see is that if this person is giving up the electron and giving it to this person over here, then, uh, this person will be gaining electrons, meaning that it will be reduced. That person will be reduced, whereas the person that is giving up electrons giving them away, they are losing electrons. And because they are losing electrons, they are being oxidized. And so you can see that theocracy Dacian reduction reactions will always go hand in hand because it's almost like a person giving a gift away. If someone's giving away a gift or losing a gift, that means that someone else is gaining the gift. And so oxidation and reduction reactions will always go hand in hand, just like what you could see here in this image. And so this year concludes our introduction to Redox reactions, and we'll be able to learn Mawr Maura about them as we move forward in our course, so I'll see you all in our next video.
2
example
Redox Reactions Example 1
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1m
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So here we have an example problem that's asking which of the following molecules is oxidized and which is reduced and notice that we have molecule a over here and molecule B and they are undergoing a chemical reaction. And so notice we have these four potential answer options over here. And so, of course, what we need to recall from our last lesson video is that when it comes toe oxidation reduction reactions or redox reactions, really, all we need to remember is Leo the lion goes ger and because if we remember Leo the lion goes ger, then we'll be able to remember that oxidation is when a substance loses electrons and reduction is when a substance gains electrons. And so, looking at this reaction here between molecule a molecule be noticed that molecule a is starting with an electron here, and blue and molecule B seems to not have those that electron and so notice that after this reaction, molecule A is actually donating its electron two molecule B, and so molecule A is losing an electron by the end of the reaction, whereas molecule B is gaining the electron. And so because molecule B is gaining the electron that makes it reduced. And because molecule A is losing the electron by the end of the reaction that makes molecule a oxidized. And so we need to choose the option that corresponds with that and notice option A says molecule is oxidized, whereas molecule B is reduced. And that is going to be the correct answer to this example. Problems. So we could go ahead and mark a here as correct. And that concludes this example problems, so I'll see you all in our next video.
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Problem
Problem
Oxidation is the _________________________, and reduction is the _________________________.
a) Gain of electrons; Loss of electrons.
b) Gain of protons; Loss of protons.
c) Loss of electrons; Gain of electrons.
d) Gain of oxygen; Loss of oxygen.
A
Gain of electrons; Loss of electrons.
B
Gain of protons; Loss of protons.
C
Loss of electrons; Gain of electrons.
D
Gain of oxygen; Loss of oxygen.
4
Problem
Problem
When glucose donates electrons to NAD+ creating NADH, the glucose molecule becomes:
a) Hydrolyzed.
b) Oxidized.
c) Neutral.
d) Reduced.
A
Hydrolyzed.
B
Oxidized.
C
Neutral.
D
Reduced.
5
concept
Electron Carriers:NADH & FADH2
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5m
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in this video, we're going to introduce electron carriers specifically and a D H and f a d h two. And so it's important to note is that many biological processes that we're going to talk about moving forward in our course, including cellular respiration, conduct redox reactions using electron carriers. And so these electron carriers air going to be helpful to perform Redox reactions. And so electron carriers such as, for example, n a. D H and F a d H two are each going to carry or transport a maximum of two electrons. And so these N a. T h and F A d H two electron carriers can shuttle electrons to different locations within a cell. Kind of like an electron taxicab. And so really, you can think of any D H and F A. D. H two as electron taxicabs, and we'll be able to see that down below and our image now. It's also important to note that n a D plus and F a d. R the oxidized forms of n a. D H and F a. D H two, respectively. And so recall that oxidized we think of Leo, and we know that Leo the lion goes girl, And so the Oh, and the, uh, Leo here represents oxidation. And so this means that n a d plus an f a d are both going to have less electrons. They're going to have lost electrons in comparison to n a. D h and F a d h two. So let's take a look at our image down below to clear some of this stuff up. And so these electron carriers that we're gonna be talking about a D h and F a D H two again, they really act like electron taxicabs. And so notice here in this image, we're showing you an electron taxi cab and over here on the left hand side noticed that we have the empty form of the electron taxicab. But of course, when this electron taxicab picks up its two passengers, these two electrons, it's going to become a full taxi cab. And so over here we have the two electrons inside of this electron taxicab. And so, really, this is what an a D H and F a d h to act as as thes electron taxicabs and so notice that n a D. H will form when the oxidized form the N a. D plus the empty taxi cab version basically picks up its two passengers. These two electrons along with the hydrogen I am, and it forms N a d h. And so you can see that in a d. H. Is carrying these two electrons these two passengers of the taxi cab, if you will. But it also picks up a hydrogen atom as well. And when we take a look at F a d over here, this is the empty taxi cab version of F a. D. This electron carrier. But when it picks up its two passengers thes two electrons, it also picks up to hydrogen ions as well. And it becomes F A. D H two and F a. D. H two is the full taxicab version off this electron carrier. Now, one way to help you guys remember, Ah helpful memory tool to help you remember that N a D h and F a D h two are the full taxicab versions is to just think that n a. D H and F A. D H two are just a little bit heavier and they're a little bit heavier because they're gaining electrons in the hydrogen, they gain electrons and hydrogen. And so the ones that have h and them are just gonna be a little bit heavier. And so those they're going to be the full taxicab versions here and here. And so what? You'll notice what you'll learn as we move forward. In our course, talking about cellular respiration is that during cellular respiration, these electrons carried by an A. D h and F A. D H two are going to go toe what's known as the electron transport chain, which is the final stage of cellular respiration. And again, we'll get to talk Mawr and Maura about this as we move forward in our course. But for now, what you can see is that this full electron taxicab here notice one of the electrons is asking, Where are we going? And the other electrons responding to the electron transport chain. Duh. And so you can remember that moving forward in our course, we're gonna learn that these any D. H is and f a. D. H two are going to take their electrons to the electron transport chain during cellular respiration. But this year concludes our brief introduction to electron carriers and a D H and F A. D H two, and we'll be able to get some practice applying the concept that we've learned here as we move forward in our course, So I'll see you all in our next video.
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Problem
Problem
An electron carrier before it harvests energy from glucose molecules in a series of gradual steps is:
a) Pyruvate.
b) AMP.
c) ATP.
d) NAD+.
e) NADH.
A
Pyruvate.
B
AMP.
C
ATP.
D
NAD+.
E
NADH.
7
concept
Electron Carrier NADPH
Video duration:
3m
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in this video, we're going to introduce yet another electron carrier and that is the electron carrier, N A D P H. And so N A D P H only differs from N A D H by this P that is present and the P represents a phosphate group. And so once again, NADPH is an electron carrier that is actually very similar to the electron carriers that we already talked about in our last lesson video, which recall RNADH and FADH two. And so N A D P H, like N A D H and F A D H two can carry two electrons and transport those electrons within the cell to different locations. And they can be used for reduction reactions or reactions that reduce other molecules and allow them to gain electrons. Now. However, unlike an A. D. H and F A D H two. N A D P H is specifically used in bio synthetic reactions for bio synthesis purposes. Or in other words it's used in reactions that are going to build molecules and cell structures. And so really you can think of this electron carrier, N A D ph as a little construction truck. And so here what we have is this construction truck that is going to be used for building for bio synthetic reactions. And so notice that the empty version of this construction truck corresponds with N A D P plus. This is the oxidized form of the electron carrier. And so it has no electrons notice that the electron spots are empty but notice that it can gain two electrons and become a full construction truck that's carrying two electrons. And so this full construction truck corresponds with the electron carrier N A D P H. Now, once again, uh N A D P H can gain two electrons and a hydrogen ion to become N A D. P H. And it's going to carry electrons from one location within the cell to a different location within the cell, very similar to the other electron carriers that we already talked about. However, one of the main important differences is that N A D P H is going to be used in bio synthetic reactions in order to build self structures and build molecules. And so here what you can see is a house that is under construction and N A D P H is going to be used to help build this house here or to build some kind of self structure with or molecule within the cell. And so that is something that you do want to keep in mind is N A D P H is going to be used for bio synthetic reactions to build molecules and cell structures. And so this year concludes our brief lesson on the electron carrier N A D P H. And we'll be able to see this electron carrier as we move forward throughout our course. But for now this here concludes this video and I'll see you all in our next one
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Problem
Problem
NADH is commonly used as an electron carrier during the breaking down of complex molecules like glucose in cellular respiration. NADPH is also a common electron carrier. However, NADPH is used to build complex molecules like glucose in a process called:
A
Biogenesis.
B
Biocatalysis.
C
Biosynthesis.
D
Metabolism.
9
Problem
Problem
Which electron carrier is not matched with its correct function.
A
NADH:Shuttles electrons to regions of the cell which need energy.
B
FADH2:Shuttles electrons to the electron transport chain during cellular respiration.
C
NADPH:Shuttles electrons to photosynthesis where glucose molecules are being made.
D
All of the above electron carriers are matched with their correct function.
