Question

A competitive enzyme inhibitor.

• A. Alters the Vmax but does not alter Km of the enzyme
• B. Alters the Km but does not alter the Vmax of the enzymes
• C. Alters both Km and Vmax of the enzymes
• D. Does not alter either the Km or Vamx of the enzyme

Answer 1

The correct option is B Alters the Km but does not alter the Vmax of the enzymes

Vmax is the maximum velocity of the enzyme. The Michaelis constant (KM) is defined as the substrate concentration at which the reaction rate is half of its maximal value. Competitive inhibitors can only bind to enzyme [E] and not to enzyme substrate complex [ES]. They increase Km by interfering with the binding of the substrate, but they do not affect Vmax because the inhibitor does not change the catalysis in ES because it cannot bind to ES.

So, the correct option is 'B'.