This chapter contains a lengthy discussion of the trp operon involved in regulating the synthesis of tryptophan. In the case of E. coli, the bacterium may need to synthesize tryptophan, or its host, a human, may supply all the tryptophan it needs. Why do both bacteria and humans need tryptophan?

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?

Under what conditions does the trp repressor block transcription of the trp operon?

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