Final answer:
CTP's allosteric inhibition of the first enzyme in its synthesis pathway is an example of feedback inhibition, a regulatory mechanism in which the end product of a reaction inhibits an enzyme earlier in the pathway to control biochemical reaction rates and maintain homeostasis.
Step-by-step explanation:
The scenario described where cytidine triphosphate (CTP) allosterically inhibits the first enzyme in the multiple-step reaction pathway for its own synthesis is an example of feedback inhibition. This is a biological mechanism in which the final product of a metabolic pathway inhibits an enzyme that is involved earlier in the pathway. In this case, the inhibitory effect of CTP occurs by binding to the allosteric site of the enzyme rather than the active site, inducing a conformational change that reduces the enzyme's activity. This regulation ensures that when CTP is abundant in the cell, its further production is curtailed, preventing the waste of resources and maintaining metabolic balance.
Regulation of pathways through feedback inhibition is a common cellular strategy to control the levels of various substances, such as enzymes, nucleotides, and other metabolites within the cell. When levels of CTP rise, it binds to the allosteric site of the first enzyme in the pathway, inducing a structural change in the enzyme and decreasing its affinity for the substrate. The overall effect is a decrease in the pathway's activity, thereby reducing the production of CTP.