They convert glucose into usable energy.
The correct sequence is; Glycolysis-pyruvate-acetyl CoA-krebs cycle-electron transport chain.
Glycolysis is a sequence of reactions for the breakdown of glucose to two molecules of pyruvic acid under aerobic conditions, Krebs cycle is a series of chemical reactions used by all aerobic organisms to release stored energy through the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins into carbon dioxide and chemical energy in the energy carriers, while electron transport chain involves a series of complexes that transfer electrons from electron donors to electron acceptors via redox reactions and couples this transfer with the transfer of protons across a membrane.
