Which effect regarding competitive inhibition is NOT true?

Prepare for the NBEO Biochemistry Exam with our comprehensive quizzes. Study effectively with interactive flashcards and detailed explanations, enabling you to grasp complex concepts effortlessly. Get exam-ready today!

In the context of competitive inhibition, the assertion that Vmax increases is not true. In competitive inhibition, a substance competes with the substrate for binding to the active site of the enzyme. While this competition increases the apparent Km (Michaelis constant) because a higher concentration of substrate is required to overcome the inhibitor's effects, Vmax—the maximum rate of the reaction—remains unchanged. This is because, at sufficiently high concentrations of substrate, the inhibitor can be outcompeted, allowing the enzyme to achieve its maximum catalytic efficiency, which is defined by Vmax.

In terms of the Lineweaver-Burk plot, which is a double reciprocal plot of enzyme kinetics, an increase in Km due to competitive inhibition would manifest as a shift of the x-intercept to the right. The rightward shift indicates a higher rate of substrate concentration is necessary to reach half of Vmax when the inhibitor is present.

Thus, the assertion about Vmax increasing in competitive inhibition is incorrect since competitive inhibitors do not change the maximum rate of the enzymatic reaction, only the amount of substrate required to reach that maximum efficiency with respect to affinity and Km.

Subscribe

Get the latest from Examzify

You can unsubscribe at any time. Read our privacy policy