Glycolysis that generates pyruvate is linked to the tricarboxylic acid cycle (TCA cycle also named citric acid cycle or Krebs cycle), that takes place within mitochondria, is a series of enzyme-catalyzed chemical reactions that form a key part of aerobic respiration in cells and is central to the regulation of energy homeostasis and cell metabolism. It is the gateway to the aerobic metabolism of any molecule (glucid, lipid, protein) that can be transformed into an acetyl group or a dicarboxylic acid.