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Cell Biology

Learn the toughest concepts covered in Cell Biology with step-by-step video tutorials and practice problems by world-class tutors

3. Energy

Enzyme Inhibitors


Enzyme Inhibition

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Hi in this video we're gonna be talking about enzyme inhibition. So what do enzyme inhibitors do? Will they decrease enzymatic activity? And you can imagine why that needs to happen. Enzyme speed up reactions. But we don't always need reactions speed up. Sometimes we needed 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 two main types of enzyme inhibitors. These can be reversible or irreversible. So irreversible inhibitors actually bind so tightly to the enzyme through covalin functions. And because they're bound so tightly they just inhibit the function um and you know, never let go. And so these are really irreversible there 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 um 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 buying more weekly usually through non violent interactions. Um and because they bind weakly that means that they are reversible. So they those bonds and those non violent interactions can be broken so that they can release their inhibitory activity. Now there are two types of reversible inhibitors. These are competitive and noncompetitive. Um And you may see noncompetitive will also be referred to as a lost erIC And essentially the competitive ones do exactly what you would think. They actually compete with the substrate for the active site and the non competitive ones or the A list erIC do not compete with the substrate for the active site. So um Well I'm gonna show you an image to really like get those definitions down. But first I want to say that enzymes are crucial for the regulation of cellular chemical reactions. Um But like I said before they can be harmful things like nerve gas and stuff. Um But they're very important for regulation. So now let's look at different types of um inhibition of enzymes. So first we have the normal enzyme uh you know, experience or reaction. They have the enzyme here. The substrate here they bind and that makes products or yeah products that are released. Now if we want to inhibit enzyme we can do this competitively E. L. Y. Or non competitively. So first through the competitive you can see that there's 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 um the enzyme substrate comes in it's found that its active site has actually changed shape. You can see here where it's this um you know, corner formation where this has this boxy formation so the substrate no longer fits or is 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 um enzyme inhibition. So now let's move on.

Which of the following enzyme inhibitors binds through covalent bonds?


Which of the following enzyme inhibitors binds to the enzymes active site to inhibit the enzyme?