What role do coenzymes play in biochemical reactions?

Coenzymes play a critical role in biochemical reactions primarily by assisting enzymes in catalyzing those reactions. These are small, organic molecules that often act as carriers for specific atoms or functional groups that participate in the enzymatic reaction.

For example, coenzymes such as NAD+ and FAD are vital in oxidation-reduction reactions, transferring electrons between molecules. They often facilitate the conversion of substrates into products by temporarily binding to the enzyme and participating directly in the chemical transformations taking place. This interaction allows the enzyme to perform its catalytic function more effectively, thereby speeding up the reaction and increasing overall metabolic efficiency.

In contrast, the other options suggest functions that do not accurately reflect the nature of coenzymes. Stating that coenzymes solely stabilize proteins overlooks their active role in reaction mechanisms. Moreover, describing them as permanent components of enzymes is misleading, as coenzymes typically bind transiently to the enzyme. Lastly, while coenzymes do participate in metabolic pathways, they are not exclusively limited to these pathways; their flexibility allows them to engage in various biochemical reactions beyond just metabolism.