Which statement about competitive inhibition of enzymes is accurate?

• A. It decreases the maximum velocity of the reaction
• B. It can be overcome by increasing substrate concentration
• C. It permanently inactivates the enzyme
• D. It changes the shape of the enzyme irreversibly

Answer: (B)

Competitive inhibition involves a molecule competing with the substrate for binding to the active site of the enzyme. This means that as the concentration of the substrate increases, it can outcompete the inhibitor for the active site, allowing the reaction to proceed. In essence, if enough substrate is present, it can effectively "overcome" the effect of the competitive inhibitor.

This characteristic of competitive inhibition is what distinguishes it from other types of inhibition, such as non-competitive inhibition, where the inhibitor binds to a different site on the enzyme and thus cannot be easily overcome by simply increasing substrate concentration. The maximum velocity (Vmax) of the reaction remains unchanged in competitive inhibition since if enough substrate is provided, the enzyme can still achieve its maximum activity.

Therefore, the statement that competitive inhibition can be overcome by increasing substrate concentration is accurate and reflects a critical understanding of enzyme kinetics and the dynamics of inhibition.