In the tryptophan operon, which molecule serves as the corepressor by binding to the repressor?

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Multiple Choice

In the tryptophan operon, which molecule serves as the corepressor by binding to the repressor?

Explanation:
The tryptophan operon is regulated by a repressor that needs a ligand to become active. The repressor protein by itself cannot bind the operator. When tryptophan levels are high, tryptophan binds to the repressor, inducing a conformational change that lets the repressor attach to the operator and block RNA polymerase, stopping transcription of the operon. This means the cell stops making more tryptophan when it’s plentiful. Indole is a related metabolite in the pathway but does not act as the corepressor in this regulatory system, while guanine and thymine are simply nucleotides and do not function as regulators here.

The tryptophan operon is regulated by a repressor that needs a ligand to become active. The repressor protein by itself cannot bind the operator. When tryptophan levels are high, tryptophan binds to the repressor, inducing a conformational change that lets the repressor attach to the operator and block RNA polymerase, stopping transcription of the operon. This means the cell stops making more tryptophan when it’s plentiful. Indole is a related metabolite in the pathway but does not act as the corepressor in this regulatory system, while guanine and thymine are simply nucleotides and do not function as regulators here.

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