The scheme below represents a hypothetical metabolic pathway for the synthesis of compound Y. The pathway is regulated by feedback inhibition. If S → T is the rate-limiting step, circle what the most likely inhibitor is and indicate with an arrow where the inhibition most likely occurs: S → T → U → V → W → X → Y

So this practice problem says the scheme below shown right here represents a hypothetical metabolic pathway for the synthesis of compound y and notice that compound y is the final product of this metabolic pathway. And so it says that this pathway is regulated by feedback inhibition, and we know from our previous lesson videos that feedback inhibition is also known as negative feedback. And so, if the reaction that converts molecule s into molecule t shown right here in the metabolic pathway is the rate limiting step, which is recall the slowest step of the entire metabolic pathway, then circle what the most likely inhibitor is and indicate with an arrow where the inhibition most likely occurs. Now, because this particular reaction right here is the slowest rate limiting step, it actually makes this reaction the key step to controlling this entire metabolic pathway because remember that a metabolic pathway can only proceed as fast as its slowest rate limiting step. And so, because this is the key reaction, essentially, this reaction is going to be, the reaction that we are going to want to regulate by feedback inhibition in order to control this entire metabolic pathway. And of course, because this is feedback inhibition, it's gonna be represented by a negative sign like this. And so, now that we've determined, exactly where the inhibition is most likely to occur, we're going to now circle the most likely and the most likely inhibitor of a metabolic pathway is going to be the final product. And so why here the final product is likely to be the allosteric inhibitor that regulates the enzyme that, converts this reaction right here, that catalyzes this reaction. And so now that we've circled the most likely inhibitor and we've indicated with an arrow where the inhibition most likely occurs, This practice problem is complete, and so I'll see you guys in our next video.

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Negative Feedback practice set