500
The trp operon is a/an __________(inducible/repressible) operon. The trp genes encode products involved in the __________(anabolism/catabolism) of tryptophan. When tryptophan binds to the repressor, the repressor_______ (binds to/falls off) the operator, and transcription ________ (occurs/does not occur).
What is repressible, anabolism, binds to, does not occur?