If a particular operon encodes enzymes for making an essential amino acid and is regulated like the trp operon, then
A) the amino acid inactivates the repressor.
B) the enzymes produced are called inducible enzymes.
C) the repressor is active in the absence of the amino acid.
D) the amino acid acts as a corepressor.
E) the amino acid turns on transcription of the operon.

Question

Quizplus · Accepted Answer

If the operon encodes enzymes for making an essential amino acid and is regulated like the trp operon, then the amino acid acts as a corepressor, which binds to the repressor protein and activates it, preventing transcription of the operon. This negative feedback loop ensures that the cell only produces the amino acid when necessary and avoids wasting resources.

If a Particular Operon Encodes Enzymes for Making an Essential