Control over nitrogenase activity is accomplished by which of the following?
a. atp serves as an allosteric activator
b. amp serves as an allosteric inhibitor
c. nh4+ prevents expression of the genes that encode nitrogenase
d. phosphorylation prevents activity
e. none of the above

C

Explanation:

Control over nitrogenase activity is accomplished by  NH4+ prevents expression of the genes that encode nitrogenas.

Nitrogenase synthesis in free-living N2-fixing bacteria is universally under repressor control by ammonia. This, however, is not

the case for rhizobia. A need for N2 as inducer apparently does not

exist.  The degree of ammonia repression is unusual in its strength.

Nitrogenase activity is at least 1O,OOO-fold lower in extracts of

NH4+-grown cells versus N2-grown cells.

the earth would become to overheated and everything alive on it will eventually die from overheating. plants will eventually die as well, water will evaporate, and it will be nothing but a hot planet without anything living on it.

the answer is c

tell me if wrong