Animation of the pyruvate dehydrogenase complex (PDC). This is a complex of three enzymes found in the mitochondria of cells, which decarboxylates pyruvate into acetyl-CoA. In this animation, small white molecules of pyruvate fall into the complex, and larger molecules of acetyl-CoA pour out. Acetyl-CoA is an important biochemical, which is subsequently used in the Krebs cycle, which is central to cellular respiration. The PDH complex therefore provides the link between glycolysis, the breakdown of sugars from food, with respiration, the process that cells use to produce energy. The depicted speed of reaction in this clip is only about one third of the real speed in cells.