True about reversible non-competitive inhibitors
**Core Concept**
Reversible non-competitive inhibitors are a type of enzyme inhibitor that binds to a site other than the enzyme's active site, thereby reducing the enzyme's activity without altering its affinity for the substrate. This type of inhibition is characterized by a decrease in the maximum velocity (Vmax) of the enzyme-catalyzed reaction without affecting the Michaelis constant (Km).
**Why the Correct Answer is Right**
Reversible non-competitive inhibitors bind to a region of the enzyme that is not involved in substrate binding, often referred to as an allosteric site. This binding causes a conformational change in the enzyme, leading to a decrease in its activity. As a result, the enzyme's Vmax is reduced, but its affinity for the substrate remains unchanged. This can be represented by the following equation: V = Vmax * [S] / (Km + [S]), where V is the reaction velocity, Vmax is the maximum velocity, [S] is the substrate concentration, and Km is the Michaelis constant.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the mechanism of reversible non-competitive inhibition.
**Option B:** This option is incorrect because it describes the effect of a competitive inhibitor, which increases Km without affecting Vmax.
**Option C:** This option is incorrect because it describes the effect of a irreversible inhibitor, which permanently inactivates the enzyme.
**Option D:** This option is incorrect because it describes the effect of an uncompetitive inhibitor, which decreases Km and Vmax.
**Clinical Pearl / High-Yield Fact**
Reversible non-competitive inhibitors can be used to modulate enzyme activity in a reversible and specific manner, making them useful in various therapeutic applications, such as the treatment of certain diseases or the regulation of metabolic pathways.
**Correct Answer: A.