Question

The protein portion of an enzyme is called:

• A. Coenzyme
• B. Apoenzyme
• C. Prosthetic group
• D. Cofactor

Hint:

Remember the acronym: \textbf{Holoenzyme = Apoenzyme + Cofactor}. The apoenzyme is the protein part.

Answer 1

The Correct Option is B

Enzymes, biological catalysts, often necessitate non-protein components known as cofactors for function. The protein component alone is termed an apoenzyme. Upon binding with its cofactor, the apoenzyme forms a holoenzyme, the fully active enzyme. Organic cofactors are classified as coenzymes, while cofactors tightly attached to the apoenzyme are prosthetic groups. Cofactors is a general term that includes both coenzymes and prosthetic groups. Consequently, only the apoenzyme designates the protein fraction.