Catabolisms are biochemical processes that break down complex molecules to provide energy for cellular activity. Alternative terms that can be used to describe catabolisms include metabolism, which is the collective term for all biochemical processes in the body, or catabolic reactions, which refers specifically to the breakdown of larger molecules into smaller components. Other synonyms for catabolisms include degradation, disintegration, decomposition, and breakdown. Each of these terms captures different aspect of the process of catabolism, from the physical breaking apart of molecules to the chemical changes that occur during the process of energy production. Despite their differences, these terms are all useful for describing the vital role that catabolic reactions play in sustaining life.