The pyruvate molecules made in glycolysis move from the cytoplasm to special structures in the cell called mitochondria, where the remaining steps of cellular respiration are carried out. Each mitochondrion contains a membrane that is folded back and forth many times. This extensive membrane is studded with hundreds of thousands of enzymes that direct cellular respiration. The numerous enzymes enable great quantities of ATP to be produced simultaneously in one mitochondrion. Without mitochondria or a similar structure, most cells could not generate enough ATP to survive.
The transition stage is a short biochemical pathway that links glycolysis with the Krebs cycle. In this brief stage, enzymes transfer hydrogens a