Question

Vitamins with some enzymes act as

• A. Apoenzyme
• B. Cofactor
• C. Holoenzyme
• D. Co-enzyme

Answer 1

Answer: (D)

Vitamins with some enzymes act as coenzyme. Coenzymes are organic non protein molecules that bind with the protein molecule (apoenzyme) to form the active enzyme (holoenzyme). A number of the water-soluble vitamins such as vitamins B${}_1$, B${}_2$ and B${}_6$ serve as coenzymes.

An apoenzyme is an inactive enzyme, activation of the enzyme occurs upon binding of an organic or inorganic cofactor.

Holoenzyme is an apoenzyme together with its cofactor. A holoenzyme is complete and catalytically active.

A cofactor is a non-protein chemical compound that is required for the protein's biological activity. These proteins are commonly enzymes, and cofactors can be considered "helper molecules" that assist in biochemical transformations.

Therefore, the correct answer is option A.