What distinguishes coenzymes from cofactors?

Coenzymes are distinguished from cofactors primarily by their organic nature. They are organic molecules that often serve as carriers for specific atoms or functional groups during enzymatic reactions, playing a crucial role in the function of enzymes by contributing to the chemical transformations that occur. Common examples of coenzymes include NADH, FADH2, and various vitamins.

In contrast, cofactors can be either inorganic ions, such as metal ions like zinc or magnesium, or organic molecules. While some cofactors are organic, the presence of coenzymes specifically refers to the organic aspect, making option C accurate in highlighting this important distinction. This understanding is fundamental to the study of biochemistry and enzymology, where the roles of coenzymes and cofactors in metabolic processes are critical for comprehending how enzymes function in biological systems.