What chemical process involves breaking down complex molecules by the addition of water?

The chemical process that involves breaking down complex molecules by the addition of water is hydrolysis. In hydrolysis, water molecules facilitate the cleavage of bonds in larger molecules, resulting in the formation of smaller units, such as monomers from polymers. This process is critical in biological systems, as it plays a significant role in digestion. Enzymes often catalyze hydrolysis reactions to break down macromolecules like carbohydrates, proteins, and lipids into their constituent small molecules, which the body can then utilize.

For example, in the digestion of starch, hydrolysis converts polysaccharides into simple sugars by adding water to the glycosidic bonds. Thus, hydrolysis is essential for making nutrients available and enabling cellular reactions.