Question

Competitive inhibitor increases
• \(V_{\max}\)
• Enzyme concentration
• Product formation
• \(K_m\)

• A. Vmax
• B. Enzyme concentration
• C. Product formation
• D. Km

Hint:

Competitive inhibition: \[ K_m \uparrow \] \[ V_{\max} = \text{constant} \]

Answer 1

The Correct Option is D

Concept: Competitive inhibition occurs when:
• Inhibitor resembles substrate
• Inhibitor competes with substrate for active site of enzyme In competitive inhibition:
• Apparent \(K_m\) increases
• \(V_{\max}\) remains unchanged

Step 1: Understand Michaelis constant \(K_m\). Michaelis constant represents: \[ \boxed{ \text{Substrate concentration required for half maximum velocity} } \] Higher \(K_m\) means:
• Lower enzyme affinity for substrate

Step 2: Understand action of competitive inhibitor. Competitive inhibitor:
• Occupies enzyme active site
• Prevents substrate binding temporarily Thus:
• More substrate is required to achieve same reaction rate. Hence apparent \(K_m\) increases.

Step 3: Understand why \(V_{\max}\) does not change. At very high substrate concentration:
• Substrate outcompetes inhibitor
• Maximum velocity can still be achieved Therefore: \[ V_{\max} \text{ remains unchanged} \]

Step 4: Analyze options.
• \(V_{\max}\) does not increase.
• Enzyme concentration remains same.
• Product formation generally decreases initially.
• \(K_m\) increases. Thus correct answer is: \[ \boxed{ K_m } \]

Step 5: Choose correct answer. Hence correct option is: \[ \boxed{(4)} \] Final Conclusion: Competitive inhibition: \[ \boxed{ K_m \uparrow,\quad V_{\max}\ \text{unchanged} } \] Hence correct answer is: \[ \boxed{(4)} \]