How can a cell respond to the addition of arginine to the medium by shutting off the enzyme involved in its...

Question

synthesis without affecting protein synthesis?

A)some excess arginine molecules will occupy active sties.

B)Some of the excess arginine molecules will occupy allosteric sties on the enzyme involved in the synthesis

C)Covalent modification of the enzyme occurs

D)The ATP/ADP ratio in the cell becomes unfavorable

E)THe NAD /NADH ratio in the cell becomes unfavorable.

I think its B, but I'm not sure...any help would be great

Answer 1

B)Some of the excess arginine molecules will occupy allosteric sties on the enzyme involved in the synthesis.

This would be an example of end product inhibition - a common way of controlling meatbolic pathways and shutting off synthesis when the end product is in excess and further synthesis is not needed.

As an example,

isoleucine controls its own synthesis by inhibiting threonine deaminase;

adenosine 5¢-triphosphate (ATP) and citrate control glycolysis by

inhibiting phosphofructokinase.