Apentix/AP Biology/Unit 3: Cellular Energetics/Question
AP Biologymediummcq1 pt

In many biosynthetic pathways, accumulation of the final product inhibits an enzyme acting early in the route, often at an allosteric site. Why is this arrangement advantageous?

A.It guarantees the pathway always runs at maximum velocity regardless of demand.
B.It prevents wasteful overproduction by throttling the pathway whenever the end product is already plentiful.
C.It permanently destroys the early enzyme so the gene can evolve a replacement.
D.It raises the enzyme's affinity for its substrate precisely when the product is abundant.

Explanation

Core Concept

Allosteric feedback ties pathway activity directly to need. When the end product accumulates, binding at a distant regulatory site deforms the early enzyme and slows the whole route before intermediates pile up. Precursors and the ATP spent converting them are conserved, and when product levels drop, inhibition lifts automatically and flux resumes without any new signal.

Correct Answer

BIt prevents wasteful overproduction by throttling the pathway whenever the end product is already plentiful.

More Unit 3: Cellular Energetics practice questions

Try a random question →

Practice more AP Biology questions with full explanations

Practice Unit 3: Cellular Energetics Questions →