The document discusses aerobic respiration which takes place in almost all living things and results in the maximum release of energy from glucose. It occurs in three stages: glycolysis, the Krebs cycle, and the electron transport chain. Glycolysis breaks down glucose in the cytoplasm and produces a small amount of ATP. The Krebs cycle further breaks down these products in the mitochondria through a series of chemical reactions. Finally, the electron transport chain passes electrons through protein complexes in the membranes to produce ATP through oxidative phosphorylation.