Which of the following occurs as a result of an abundance of tryptophan in e. coli?

a) the 5 trp genes (trpa - trpe) are not transcribed.
b) stalling of the ribosome at trp codons in the leader sequence
c) the 5 trp genes (trpa - trpe) are transcribed, but not translated.
d) the leader sequence is not transcribed.

A) The 5 trp genes (TrpA - TrpE) are not transcribed.

Explanation:

enzyme active site and substrate specificity

enzymes bind with chemical reactants called substrates. there may be one or more substrates for each type of enzyme, depending on the particular chemical reaction. in some reactions, a single-reactant substrate is broken down into multiple products

these muscles maintain the blood pressure in the vessels. the smooth muscles are innervated by nerves of the autonomic nervous system. when the muscles contract, they cause vasoconstriction of the vessels and increase blood pressure. when the muscles relax, they enable vasodilation of the   blood vessels hence reduce blood pressure.