1. All genes are not "on" all the time. Using the metabolic needs of E. coli, explain why not.
2. What are the two main ways of controlling metabolism in bacterial cells?
3. Feedback inhibition is a recurring mechanism throughout biological systems. In the case of E. coli regulating tryptophan synthesis, is it positive or negative inhibition? Explain your choice.
4. What is a promoter?
5. What is the operator? What does it do?
6. What is an operon?