Metabolism

Set of chemical reactions in organisms

Metabolism (from Greek μεταβολή (metabolē) 'change') refers to the set of life-sustaining chemical reactions that occur within living organisms. The three main functions of metabolism are the conversion of energy in food into a usable form for cellular processes; the conversion of food to building blocks of macromolecules (biopolymers) such as proteins, lipids, nucleic acids, and some carbohydrates; and the excretion of metabolic wastes. These enzyme-catalyzed reactions allow organisms to grow, reproduce, maintain their structures, and respond to their environments.

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