The citric acid cycle is a series of enzyme-catalysed chemical reactions of central importance to all living cells that use aerobic respiration. In eukaryotes, the citric acid cycle occurs in the matrix of the mitochondrion. In conjunction with glycolysis and oxidative phosphorylation, it is responsible for the chemical conversion of carbohydrates, lipids and proteins into a usable form of energy, such as ATP, in a process that generates carbon dioxide and water as waste products.Image credit: YassineMrabet