Hi. In this video, we're going to be talking about enzyme inhibition. So, what do enzyme inhibitors do? Well, they decrease enzymatic activity. And, you can imagine why that needs to happen. Enzymes speed up reactions, but we don't always need reactions speeded up. Sometimes, we need them stopped. And in the cases that we need them stopped, we need things that can regulate enzymes, and these are typically enzymes inhibitors. So, there are 2 main types of enzyme inhibitors. These can be reversible or irreversible. So irreversible inhibitors actually bind so tightly to the enzyme through covalent bonds. And because they're bound so tightly, they just inhibit the function, and, you know, never let go. So, these are really irreversible. The enzyme will never be activated again. So, a good example of this is actually nerve gas, which, you know, is lethal. And that's because it binds to these enzymes and it never lets go and it ends up in death. It doesn't have to end up in death. Not all of our irreversible inhibitors end up in death, but, a lot of them do, because you have to be able to reverse it to control and regulate the reaction. Now, the second type is the reversible inhibitors, and these bind more weakly, usually through non-covalent interactions. And because they bind weakly, that means that they are reversible. So, those bonds and those non-covalent interactions can be broken, so that they can release their inhibitory effect. They will also be referred to as allosteric. And, essentially the competitive ones do exactly what you would think, they compete with the substrate for the active site. And the non-competitive ones, or the allosteric, do not compete with the substrate for the active site. So, I'm going to show you an image to really get those definitions down. But, first, I want to say that enzymes are crucial for the regulation of cellular chemical reactions. But like I said before, they can be harmful, things like nerve gas and stuff, but they're very important for regulation. So now, let's look at different types of inhibition of enzymes. So, first, we have the normal, enzyme experience or reaction. So the enzyme here, the substrate here, they bind, and that makes products, or yeah, products that are released. Now if we want to inhibit an enzyme, we can do this competitively or non-competitively. So, through the competitive approach, you can see that there is this inhibitor here that actually binds to the same place that the substrate binds. So, when the substrate comes in and tries to bind, it's unable to. And, that actually inhibits it. Now, for the non-competitive, you can see that the inhibitor comes in and actually binds to this separate site. So, that when the enzyme, the substrate comes in, it is found that its active site has actually changed shape. As you can see here, where it's this corner formation, while it was this boxy formation. So, the substrate no longer fits, or it's no longer attracted to the enzyme, but, and so it somehow inhibits the product formation and the chemical reaction occurring. So, those are two forms of reversible enzyme inhibition. So, now let's move on.
3. Energy
Enzyme Inhibitors
3. Energy
Enzyme Inhibitors - Video Tutorials & Practice Problems
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concept
Enzyme Inhibition
Video duration:
4mPlay a video:
Video transcript
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Problem
ProblemWhich of the following enzyme inhibitors binds through covalent bonds?
A
Reversible
B
Irreversible
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Problem
ProblemWhich of the following enzyme inhibitors binds to the enzymes active site to inhibit the enzyme?
A
Reversible
B
Irreversible
C
Competitive
D
Non-Competitive