[Campbell Biology P.211] A metabolic pathway is regulated by feedback inhibition. What is th... | Practice Question

A metabolic pathway is regulated by feedback inhibition. What is the typical mechanism of this regulation Concept 8.5 ?

  • A: The initial substrate of the pathway binds to and activates an enzyme later in the pathway.
  • B: The end product of the pathway allosterically inhibits an enzyme at an earlier step in the pathway.
  • C: An enzyme in the pathway is irreversibly denatured by the accumulation of a product.
  • D: Multiple enzymes in the pathway bind to each other, forming a complex that speeds up the reaction.

Explanation

Feedback inhibition is a common mode of metabolic regulation where the end product of a metabolic pathway acts as an allosteric inhibitor of an enzyme earlier in the pathway. This prevents the cell from wasting resources by synthesizing more product than is needed, effectively turning off the pathway when the product accumulates.