The cofactors NAD⁺, Cu²⁺, Zn²⁺, coenzyme A, FAD, and Ni²⁺ are all needed by your body for enzymatic reactions.
a. Which cofactors are coenzymes?

Cofactors are non-protein chemical compounds that assist enzymes in catalyzing reactions. They can be metal ions like Cu²⁺ and Zn²⁺, or organic molecules. Coenzymes are a specific type of cofactor that are organic molecules, often derived from vitamins, and are necessary for enzyme function. Understanding the distinction between these terms is crucial for identifying which cofactors in the question are classified as coenzymes.

Coenzymes play a vital role in enzymatic reactions by acting as carriers for chemical groups or electrons. They often participate in the reaction by temporarily binding to the enzyme and substrate, facilitating the conversion of substrates into products. Examples include coenzyme A and FAD, which are involved in various metabolic pathways, highlighting their importance in biochemical processes.

Common examples of coenzymes include NAD⁺, FAD, and coenzyme A. NAD⁺ is crucial for redox reactions, while FAD is involved in the citric acid cycle and fatty acid oxidation. Coenzyme A is essential for the synthesis and oxidation of fatty acids and the metabolism of carbohydrates. Recognizing these examples helps in understanding which cofactors listed in the question are coenzymes.