Which of the following represents a covalent modification of an enzyme which can be reversed
A) zymogen to enzyme.
B) change in enzyme activity with pH.
C) phosphorylation of a serine -OH.
D) allosteric modification.
E) competitive inhibition.

Question

Quizplus · Accepted Answer

Phosphorylation of a serine -OH is a covalent modification that can be reversed through dephosphorylation, which allows for regulation of enzyme activity. Zymogen to enzyme conversion is not a covalent modification, but rather a cleavage of an inactive precursor to form an active enzyme. Change in enzyme activity with pH, allosteric modification, and competitive inhibition are not reversible covalent modifications.

Which of the Following Represents a Covalent Modification of an Enzyme