Question

1. An enzyme can be regulated by

A. non-covalent interactions with regulatory molecules that bind the active site

B. non-covalent interactions with allosteric regulatory molecules

C. covalent modifications by phosphorylation

D. all of the above

2. Allosteric regulation mechanisms can cause an enzyme to be

		activated
		inhibited
		both 1 or 2
		degraded

Answer 1

Ans ) The correct answer is "D" i.e all of the above

( Enzymes can be regulated by both covalent as well as non-covalent modifications. Allosteric effectors also plays a crucial role in the regulation of allosteric enzymes which will be discussed in detail below).

Ans 2) The correct answer is "C" i.e both 1 or 2

(Allosteric modulator or effector or modifiers can bind to the allosteric site of an enzyme and can regulate the enzyme activity.If the allosteric effector is activator then positive effect is observed and if the allosteric effector is repressor then inhibitory effect or negative effect is observed. If the allosteric effector is activator then the Vmax reach very fast as compared to when the allosteric effector is repressor).