Question

How does an allosteric inhibitor work?

Choose one:
A. It binds to a site other than the active site, causing a conformational change in the enzyme that makes the active site less accommodating to the substrate.
B. It outcompetes the substrate molecule and binds to the active site, preventing substrate molecules from binding there.
C. It binds to a site other than the active site, causing a conformational change in the enzyme that forces the product to leave the active site.
D. It interacts covalently with the substrate, preventing it from fitting into the enzyme's active site.

Answer 1

An allosteric inhibitor binds to an enzyme away from the active site, inducing a conformational change that decreases substrate affinity and inhibits enzyme activity.

Step-by-step explanation:

An allosteric inhibitor is a molecule that binds to an enzyme at an allosteric site, which is different from the active site where substrate molecules normally bind. This allosteric binding causes a conformational change in the enzyme, modifying the active site of the enzyme in such a way that the affinity for the substrate decreases, making the active site less accommodating for the substrate.

This alteration prevents the substrate from binding as efficiently to the enzyme, effectively inhibiting the enzyme's catalytic activity.

Answer 2

An allosteric inhibitor binds to an allosteric site, inducing a conformational change that reduces the enzyme's active site's affinity for the substrate, thus inhibiting enzyme activity.

Step-by-step explanation:

An allosteric inhibitor works by binding to a site on an enzyme that is different from the active site, known as an allosteric site. This binding causes a conformational change in the enzyme, which then affects the active site. Specifically, it alters the shape of the active site, making it less accommodating or reducing its affinity for the substrate. Consequently, the substrate cannot bind as efficiently or at all, which inhibits the enzyme's activity and prevents the catalysis of the reaction the enzyme would normally facilitate.