1. What feature is held in common by activators such as CAP, repressors such as LacI and enzymes subject to feedback inhibition? How does this feature contribute to regulation?

2. In the simple biosynthetic pathway shown below in which precursor A is converted to endproduct E which then is used for some other purpose (protein synthesis, nucleotide synthesis, lipid synthesis etc):

A. How is the flux of metabolites through the pathway controlled by feedback inhibition?

B. What is the purpose of this regulatory mechanism?