Which of the following is a common biological example of hydrolysis?

• A. Photosynthesis
• B. Digestion of starch by amylase
• C. Combustion of glucose
• D. Evaporation of water

Answer: (B)

Hydrolysis is when a chemical bond is broken by adding water, and enzymes in living things often accelerate this process. In digestion, starch, a long chain of glucose units, is broken down by the enzyme amylase. Amylase uses water to cleave the glycosidic bonds between glucose units, producing smaller sugars such as maltose and glucose that can be absorbed by the body. This is a quintessential biological example because it shows a specific enzyme-catalyzed bond-breaking reaction that happens routinely in metabolism.

The other options describe processes that are not hydrolysis. Photosynthesis builds complex sugars from carbon dioxide and water, rather than breaking bonds with water. Combustion of glucose is an oxidation reaction releasing energy, not a hydrolysis. Evaporation is a physical change (a phase change) rather than a chemical bond-breaking reaction involving water.