Cellular respiration
Glucose broken down in a series of steps to release its bond energy in the form of electrons: each one catalyzed by an enzyme
glycolysis, Krebs cycle, electron transport chain (electron acceptors are NAD+ and FAD)
energy will be stored in usable form of bond energy: ATP (normally 36 ATP/glucose molecule)
ATP may be generated by substrate-level phosphorylation, or oxidative phosphorylation