What is the name given to the reactant of an enzyme-catalyzed reaction?

Question

Accepted Answer

Hi, everyone. Let's take a look at our next problem. Substrate is the term given to the reactant in an enzyme catalyzed reaction. Which of the following statements accurately describes or describe substrates in enzyme catalyzed reactions, select all that apply. So we have statements one through four here and then our answer choices are a one and three, B three and four, C 13 and four or D 12 and four. So let's work our way through these statements to figure out which of these are an accurate description of substrates. Statement. One says substrates bind to the active site of an enzyme forming an enzyme substrate complex. And this is correct. That is indeed how the reaction begins. Then statement two says substrates are permanently altered by the enzyme and cannot be reused in subsequent reactions since they remain bound to it. Well, this one is incorrect. The first two parts of this statement are true. They get permanently altered by the enzyme because they get transformed into product. So they can't get be reused. It's the enzyme that can be reused, but it is not because they remain bound to the enzyme once the reaction is catalyzed the, now the product is released from the enzyme. So it's the last part here that makes this statement incorrect. So since statement two is incorrect, we can rule out choice D 12 and four. And actually, we can rule out one over because we already said statement one is correct. So let's rule out statement B which only has three and four. So let's look at statement three. Statement three says substrate binding to an enzyme is highly specific often compared to a lock and key mechanism. And this is true, this is part of the magic of enzymes that they have specificity for their substrate. So statement three is correct and that doesn't let us rule anything out because both A and C have number three as a correct statement. So we just need to evaluate statement four here. The rate of the reaction increases as the substrate concentration increases until the enzyme is saturated. And this is also correct as you add more and more substrate, the reaction can happen more quickly because enzyme and substrate will meet more quickly or encounter each other more quickly. But since the enzyme isn't used up, it can be reused over and over again, then you usually only have a small amount of enzyme compared to the amount of substrate. So at a certain point, all of the enzyme present has a substrate molecule bound to it is in the process of catalyzing the reaction. So it doesn't matter how much more substrate you add, you've only got a certain amount of enzyme that can be working at a certain amount of time. So our answer then will be choice C 13 and four and we will cross out choice A one and three. So looking at these statements about substrates and enzyme catalysed reactions, our true statements are choice C 13 and four. See you in the next video.

What is the name given to the reactant of an enzyme-catalyzed reaction?

Verified video answer for a similar problem:

Key Concepts

Enzyme

Substrate

Active Site