Question

enzyme y is a component of a metabolic pathway and is inhibited by a metabolite produced at the end of that particular metabolic pathway. which statement would not be true regarding this enzyme? this enzyme uses competitive inhibition as a mechanism for its regulation by downstream metabolites in the pathway. this enzyme regulates the pathway through a feedback inhibition mechanism. this enzyme is very likely involved in the first commitment step of the metabolic pathway mentioned in the question. this enzyme may also be activated by metabolites of another pathway. levels of this enzyme may be regulated at the level of transcription of its gene.

Explanation:

1. Feedback inhibition occurs when the end - product of a metabolic pathway inhibits an enzyme earlier in the pathway. It doesn't necessarily mean competitive inhibition. The end - product can bind to an allosteric site (non - competitive inhibition).
2. Since the enzyme is inhibited by the end - product of the pathway, it is part of a feedback inhibition mechanism.
3. Enzymes in the first committed step of a pathway are often regulated by feedback inhibition to control the overall pathway.
4. Enzymes can be activated by metabolites from other pathways in a cell's complex regulatory network.
5. Gene expression regulation at the transcription level can control the amount of enzyme produced.

Answer:

The statement "This enzyme uses competitive inhibition as a mechanism for its regulation by downstream metabolites in the pathway" would not necessarily be true.