Question

Feature of competitive inhibition is

• A. $V_{max}$ increases
• B. $K_{m}$ decreases
• C. $V_{max}$ decreases
• D. $K_{m}$ increases

Hint:

Competitive: $K_{m}$ Up, $V_{max}$ Same.

Answer 1

The Correct Option is D

Step 1: Concept
Competitive inhibition occurs when an inhibitor competes with the substrate for the active site of an enzyme.

Step 2: Meaning
Kinetic parameters $V_{max}$ (maximum velocity) and $K_{m}$ (Michaelis constant) describe enzyme performance.

Step 3: Analysis
In competitive inhibition, the $V_{max}$ remains unchanged because high substrate concentrations can overcome the inhibitor. However, the apparent $K_{m}$ increases because more substrate is needed to achieve half-maximum velocity.

Step 4: Conclusion
An increase in $K_{m}$ with a constant $V_{max}$ is the hallmark of competitive inhibition.

Final Answer: (D)