What are the cellular advantages to feedback inhibition?

Question

Accepted Answer

All right. Hello everyone. So this question is asking us what are the benefits of feedback inhibition in metabolic pathways? Now, here we have four different answer choices which we'll discuss in greater detail as we proceed through this video. But for now, I very briefly want to just illustrate what feedback inhibition actually means. So let's say that I have a substrate a reacting with an enzyme which we'll call E one to produce a product B. So feedback inhibition is a mechanism in which the product of a given reaction in a metabolic pathway is going to inhibit an enzyme earlier in the pathway, including the one that produced the said product. For example, going back to our, our given here our case scenario in feedback inhibition, the enzyme E one is sensitive to the concentration of B in the system in the cell. So it's essentially responding to feedback from the concentration of product B. And so product B er an increase in the concentration of product B can act as a signal to deactivate the enzyme E one. So as soon as there's enough of product B in the cell to meet the cell's needs, E one can be deactivated for the time being. Now, when the concentration of B decreases once more, then E one can be activated to produce more of it. But the idea here is to prevent too much of product B from forming at a given time. So with this definition in mind, let's just go ahead and walk through these android choices. Option. A says that feedback inhibition leads to overproduction of end products and prevents the efficient use of resources. Now, this is incorrect because it goes against what feedback inhibition is meant to achieve. Right. Going back to our example, feedback inhibition prevents too much of product B being present in the cell at a given time. So when B is not being produced, when it's not needed, that's actually an efficient use of resources. You're not producing too much of one thing that you don't need. So A is incorrect. Now B says that it maintains homeostasis and increases toxic accumulation. Well, it's true that feedback inhibition acts to maintain homeostasis because once again, you're regulating the concentration of components of a cell, you're not increasing toxic accumulation, rather, you are preventing toxic accumulation by not allowing the concentration of a given product to increase to a dangerous extent. Now, option C says that feedback inhibition ensures metabolic efficiency, resource conservation and cellular homeostasis. This is correct, right, because we did mention previously the role of feedback inhibition in homeostasis and therefore this mechanism makes pathways more efficient because you're not spending resources on reactions that are not necessary. So that maintains homeostasis, conserves resources and makes for a more efficient metabolism overall. So C is correct, but just for the sake of completion, let's talk about. Option D, option D says that feedback inhibition hinders adaptive response and regulates pathway flux. Now, the last part is true, right? Feedback inhibition does regulate the flux of a pathway because you're essentially controlling whether or not a pathway continues in a given direction. But it doesn't hinder adaptive response. Rather. Feedback, inhibition is inherently an adaptive response, right? Because the enzyme is going to adapt to the needs of the cell by responding to that increased concentration of the product. So that's not true, which means that we can eliminate option D and therefore option C is the correct answer and there you have it. So with that being said, thank you so very much for watching. And I hope you found this helpful.

What are the cellular advantages to feedback inhibition?

Key Concepts

Feedback Inhibition

Metabolic Pathways

Cellular Homeostasis

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