Question

What is a coenzyme?

• A. Always protein
• B. Often metal
• C. Always inorganic compound
• D. Often a vitamin

Answer 1

Answer: (D)

Often a vitamin

Enzymes are simple if they are made up of only proteins, e.g., pepsin, amylase etc., while conjugate enzymes have an additional non-protein organic coenzyme or inorganic cofactor. Loosely attached organic cofactors are called as coenzymes, e.g., NAD, FAD TPP etc. Coenzymes are generally derived from vitamins like thiamine (TPP), riboflavin (FMN, FAD), niacin (NAD), pantothenate (CoA).