Final answer:
Coenzymes are essential organic helper molecules derived from dietary vitamins that support enzyme function by facilitating the transformation of substrates into products. Vitamins such as Vitamin C directly function as coenzymes in critical biosynthetic pathways like collagen formation.
Step-by-step explanation:
Coenzymes assist enzymes in chemical reactions by acting as organic helper molecules, which are essential for the enzymes' activity. These coenzymes often derive from dietary vitamins and can either be precursors to coenzymes or act directly as coenzymes. For instance, Vitamin C is a direct coenzyme for multiple enzymes that are involved in the synthesis of collagen, an important connective tissue component.
Coenzymes like NADH and ATP provide high-energy electrons or phosphate groups to enzymes, effectively enabling their catalytic activity. Without the presence of these essential coenzymes, corresponding enzymes would be inactive, known as apoenzymes; whereas enzymes with their requisite coenzymes are termed holoenzymes and are active.