Enzyme cofactors
A are needed for some enzymes to be active.
B All of these answers are correct.
C include vitamins.
D are not protein molecules.
The correct answer and explanation is:
Correct answer: B. All of these answers are correct.
Explanation (Approx. 300 Words):
Enzyme cofactors are non-protein chemical compounds or metallic ions that are required for some enzymes to carry out their catalytic activity. These cofactors assist in biochemical transformations by stabilizing enzyme structure or directly participating in the chemical reactions.
Let’s break down each option to understand why “All of these answers are correct” is the best choice:
A. Are needed for some enzymes to be active:
Correct. Some enzymes, known as apoenzymes, are inactive on their own and require a cofactor to become active (called a holoenzyme once combined with its cofactor). Without the cofactor, these enzymes cannot perform their biological function.
C. Include vitamins:
Correct. Many vitamins or their derivatives serve as coenzymes, which are a type of cofactor. For example:
- Vitamin B3 (niacin) becomes NAD⁺/NADH, a common coenzyme.
- Vitamin B2 (riboflavin) becomes FAD/FMN.
These coenzymes help transfer electrons, atoms, or functional groups during metabolic reactions.
D. Are not protein molecules:
Correct. By definition, cofactors are non-protein in nature. They can be:
- Inorganic ions, such as Mg²⁺, Fe²⁺, or Zn²⁺.
- Organic molecules, known as coenzymes, like vitamins or their derivatives.
The enzyme itself is a protein, but the cofactor is not.
Therefore, since each individual option is accurate, the correct overall answer is B. All of these answers are correct. Understanding enzyme cofactors is essential in fields like biochemistry, medicine, and nutrition because they play a crucial role in maintaining enzymatic function and overall metabolism.