Final answer:
Metabolic reactions that break down larger molecules into smaller ones are known as catabolic reactions. These reactions release energy by decomposing complex molecules like carbohydrates, lipids, and proteins into their simpler components, exemplified by the catabolic breakdown of glucose during cellular respiration.
Step-by-step explanation:
Metabolic reactions that break down larger molecules into smaller ones are classified as catabolic reactions. Catabolic reactions are exergonic and they decompose complex molecules such as carbohydrates, lipids, and proteins from ingested food into their constituent smaller parts. This process includes the breakdown of ATP, which releases the energy required for various metabolic processes in cells.
For example, the breakdown of glucose during cellular respiration is a classic catabolic reaction. It releases energy that is necessary for cells to perform life-sustaining functions. In contrast, anabolic reactions, or biosynthetic reactions, are the opposite of catabolic reactions because they construct larger molecules from smaller constituents, often requiring an input of energy from ATP.