Question

question 32
when enzyme action stops due to a buildup of end product that acts as a regulatory molecule, this control is called

a noncompetitive inhibition
b enzyme repression
c enzyme induction
d competitive inhibition

Explanation:

• Non - competitive inhibition: In non - competitive inhibition, the inhibitor (in this case, the end - product) binds to an allosteric site on the enzyme (not the active site). This binding causes a conformational change in the enzyme, making it less effective at catalyzing the reaction. As the end - product (inhibitor) builds up, it can bind to more and more enzyme molecules, effectively stopping the enzyme action.
• Enzyme repression: Enzyme repression is a regulatory mechanism at the genetic level. It involves the inhibition of enzyme synthesis (transcription and translation) rather than directly inhibiting the activity of already - present enzymes.
• Enzyme induction: Enzyme induction is the opposite of enzyme repression. It is the process by which the synthesis of an enzyme is increased (usually in response to the presence of a substrate or an inducer molecule).
• Competitive inhibition: In competitive inhibition, the inhibitor competes with the substrate for binding to the active site of the enzyme. The end - product in the given scenario is not competing for the active site (since it acts as a regulatory molecule binding to a non - active site), so it is not competitive inhibition.

Answer:

A. noncompetitive inhibition