16. Regulation of Expression

The trp operon consists of ________ genes that encode tryptophan biosynthesis enzymes.

If the trp regulatory gene mutates so that the repressor protein can no longer bind to tryptophan what will be the result?

In the absence of tryptophan, ______:

Based on the information you know about the trp operon, is the creation of tryptophan expensive to the cell?

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 repressor is active in the absence of the amino acid. c. the amino acid acts as a corepressor. d. the amino acid turns on transcription of the operon.