The process that breaks down glucose in cells to release energy is called cellular respiration. This biochemical pathway converts glucose into adenosine triphosphate (ATP), the energy currency of cells. Cellular respiration occurs in three main stages: glycolysis, the citric acid cycle, and the electron transport chain. During these processes, glucose is oxidized and energy is captured in the form of ATP, which powers various cellular activities. Additionally, the process produces carbon dioxide and water as byproducts.