🏥 USMLE Exam Prep

The Michaelis-Menten constant (Km) represents:

A Maximum reaction velocity
B The substrate concentration at which the reaction rate is half of Vmax
C Enzyme concentration
D Product concentration

✓ Correct Answer: Option B

Km = [S] at 1/2 Vmax. Lower Km = higher enzyme affinity for substrate. Competitive inhibitors increase apparent Km but don't change Vmax. Noncompetitive inhibitors decrease Vmax.

💡 Why is B) the correct answer?

The correct answer to the question "The Michaelis-Menten constant (Km) represents:" is Option B: The substrate concentration at which the reaction rate is half of Vmax.

The other options — A) Maximum reaction velocity, C) Enzyme concentration, D) Product concentration — are incorrect for this USMLE Exam Prep question. As explained above: Km = [S] at 1/2 Vmax. Lower Km = higher enzyme affinity for substrate. Competitive inhibitors increase apparent Km but don't change Vmax. Noncompetitive inhibitors decrease Vmax.

📚 About This USMLE Exam Prep Practice Question

This 3-level USMLE Exam Prep question from the Step 1 - Basic Sciences topic is part of BrainForge Quiz's free exam preparation library. Each question includes the correct answer and a detailed explanation to help you understand the underlying concept, not just memorize the answer.

How to use this page: Read the question above, consider all four options (A through D), then check the highlighted correct answer and explanation. For active timed practice, start a free USMLE Exam Prep practice test or use flashcards for spaced repetition review.

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