The term for the release of energy from chemical bonds in nutrient molecules is called cellular respiration. During this process, cells break down glucose and other organic molecules to produce adenosine triphosphate (ATP), the energy currency of the cell. Cellular respiration occurs in three main stages: glycolysis, the Krebs cycle, and the electron transport chain. Through these stages, stored energy is released, allowing organisms to perform vital functions, from muscle contraction to cell division and maintaining homeostasis.