NEET2026BiologyChapterActual
Which of the following statements correctly describes the mechanism of action of a competitive enzyme inhibitor?
Options
- AIt binds to a site other than the active site, altering the overall three-dimensional structure of the enzyme.
- BIt closely resembles the substrate in molecular structure and competes for binding at the active site.
- CIt binds irreversibly to the apoenzyme, causing permanent denaturation of the protein.
- DIt binds exclusively to the enzyme-substrate complex, preventing the release of products.
Correct answer
B. It closely resembles the substrate in molecular structure and competes for binding at the active site.
Step-by-step solution
A competitive inhibitor is a substance that closely resembles the substrate in its molecular structure. Because of this structural similarity, the inhibitor competes with the substrate for the active site of the enzyme. When the inhibitor binds to the active site, it prevents the substrate from binding, thereby reducing the rate of the enzyme-catalyzed reaction. Option (A) describes non-competitive or allosteric inhibition. Option (C) describes irreversible inhibition. Option (D) describes uncompetitive inhibition.