Question

multiple choice question

which of the following is needed for an apoenzyme to be fully functional?

substrate
denaturation
allosteric inhibitor
cofactor

Explanation:

Define apoenzyme and its activation requirements

An apoenzyme is the inactive protein portion of an enzyme that requires a non-protein helper molecule, known as a cofactor (or coenzyme), to become catalytically active.

Identify the active enzyme complex

When the apoenzyme binds with its specific cofactor, it forms a fully functional, active enzyme complex called a holoenzyme:

$$ \text{Apoenzyme (inactive)} + \text{Cofactor} ightarrow \text{Holoenzyme (active)} $$

Evaluate the given options

• Substrate: The molecule upon which an enzyme acts, but it does not activate an inactive apoenzyme.
• Denaturation: The unfolding of a protein, which destroys enzyme function.
• Allosteric inhibitor: A molecule that decreases enzyme activity.
• Cofactor: The essential non-protein component required to make the apoenzyme fully functional.

Answer:

• Substrate
• Denaturation
• Allosteric inhibitor
• Cofactor (Correct answer)