Which of the following statements correctly describes the effect of a competitive inhibitor on the kinetic parameters of an enzyme?

Solution

1. A competitive inhibitor binds to the active site of the enzyme.
2. This increases the concentration of substrate required to reach half-maximal velocity, thus increasing $K_m$.
3. At very high substrate concentrations, the inhibitor is displaced, allowing $V_{max}$ to be reached.
4. Therefore, $V_{max}$ remains unchanged while $K_m$ increases.
5. Hence the answer is (B).