Which type of enzyme regulation is best for the following situ...

Question

Which type of enzyme regulation is best for the following situations?

a. An enzyme that becomes overactive during a disease

b. An enzyme needed only when there is low blood glucose

c. An enzyme that springs into action when a traumatic injury occurs

d. An enzyme needed only during adolescence

Accepted Answer

All right. Hello everyone. So this question is asking us to choose the appropriate type of enzymatic control for the scenarios given below. Now, here we have four different scenarios labeled A through D. But before we go ahead and talk about these individually, I want to just go ahead and clarify the process of enzyme regulation and talk about the different types first. So enzyme regulation as the name implies or enzymatic control is a process used to regulate the activity of an enzyme. Right? Cells are able to turn enzymes on or off depending on the needs of the cell. Now, as mentioned before, there are four types of mechanisms, right? For enzymatic control, we have allosteric control speed back control, we have covalent modification and we also have genetic control. So starting off with allosteric control, when talking about allosteric control of an enzyme, what that essentially means is that a regulator molecule or a regulator compound in general binds to the allosteric site of a given enzyme. Now, allosteric enzymes have two types of binding sites. We have the active site, which is where the the reaction actually takes place. But the allosteric site importantly is not the active site. It is a place specifically meant for regulators to bind so that that regulator can affect the structure of the active site. So after the regulator binds to the allosteric site, the active site can either be opened or closed depending on the role of that regulator. And so from here, we have feedback control. Now, feedback control is when the product of a given reaction acts as a regulator for a given enzyme. So let's just go ahead and illustrate an example really quick. Let's say that I have an enzyme that catalyzes the conversion of starting material A into product. B. Now oftentimes a cell is careful not to produce too much of a given product because that would be inefficient, that would be devoting too much energy to something that's not necessarily needed. And so oftentimes when talking about feedback control, the concentration of B is going to affect the activity of the enzyme that binds to compound A. So essentially, if there's too much of B in the cell, that concentration of product B can effectively inactivate the enzyme, let the enzyme know that there's enough product in the cell. But from here, we have covalent modification. Now, the COVID and modification form of regulation here is essentially one groups are either added or removed from the polypeptide chain of the enzyme. Now, enzymes, the vast majority of which are proteins are sensitive to their structures because they are proteins, right. So adding or removing groups from the polypeptide chain is going to affect their structure and therefore their function. Now, there are two main forms of covalent modification. We've talked about zymogen and we've also talked about phosphorylation or dephosphorylation, which is the addition or removal of a phosphate group. Now, zymogen refer to the inactive form of an enzyme that is activated by essentially cutting parts of the polypeptide sequence, thereby producing the active enzyme. But here we're just focusing on more general definition. Thats just for your information last but not least though we have genetic control. Now, genetic control is when genes regulate the activity of certain enzymes. And this, I want to point out here is especially relevant when enzymes are only needed at specific stages of development. So now that we've talked a little bit about all of these definitions, let's go ahead and focus on scenario a to start off. So scenario A says that an enzyme or rather is asking about an enzyme that is s or excessively active in the time of an infection. So in this particular case, at the time of the infection, the enzyme becomes overactive, it becomes overactive. So here the question is how can you control the activity of an enzyme that is currently overactive? So in this particular case, a time of an infection is a special scenario, right? And so the idea is to use some kind of medication that's going to control the activity of this enzyme during this special circumstance. And so here we can often turn to competitive inhibition because competitive inhibition if you recall is when the regulator or the inhibitor competes with the starting material of the enzyme for the active site of the enzyme. So here if you have the inhibitor competing with the substrate or starting material of the enzyme that's going to control its activity because less of the substrate is going to bind to the active site. So A is competitive inhibition. And now for part B, it says an enzyme required only when there is a high level of blood sugar. So in this particular case, the enzyme in question is sensitive to the concentration of sugar in the blood. It is sensitive to the concentration of a substrate essentially because here we can assume that the enzyme is going to act on the sugar molecules themselves. Specifically, it can act to take in glucose and store it forming glycogen. So here part B is going to be an example of feedback control. And the reason it's feedback control is because the enzyme is specifically going to be sensitive to the concentration of in this case, the substrate because the enzyme would act on the sugar in the blood and store it. Now, when talking about feedback control. Earlier on in this video, I specifically talked about the role of the product as a regulator, but a substrate can also act as a regulator. So this leads us now to option C or scenario C it says that it says that an enzyme that becomes active in response to a severe burn. So, severe burns are emergency situations, right? The organism is in danger in the case of a severe bird. And so the idea is to have a mechanism that's going to act quickly on an enzyme that's needed. Right? We need the enzyme to be able to respond quickly to this emergency situation, to try and mitigate the damage as much as possible. And so what's needed for that is covalent modification because covalent modification is ideal for the quick activation or deactivation of an enzyme. All you would need to do is modify the structure of that enzyme. So C is covalent modification. And now scenario D says an enzyme required only in the course of pregnancy. So, pregnancy is a specific stage in development and genetic control describes the regulation of enzymes based on gene products. So it makes sense to say that genes that are activated only during pregnancy would activate enzymes only relevant to the course of pregnancy. So G or excuse me, D is genetic control and that completes all four parts and there you have it. So with that being said, thank you so very much for watching. And I hope we found this helpful.

Which type of enzyme regulation is best for the following situations?
a. An enzyme that becomes overactive during a disease
b. An enzyme needed only when there is low blood glucose
c. An enzyme that springs into action when a traumatic injury occurs
d. An enzyme needed only during adolescence

Key Concepts

Enzyme Regulation

Feedback Inhibition

Inducible Enzymes

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