Energy yields from anaerobic and aerobic respiration

• Energy from cellular respiration is derived in two ways : substrate-level phosphorylation (glycolysis and Krebs Cycle) and oxidative phosphorylation (electron transfer chain).
• Substrate-level phosphorylation occurs in glycolysis and the Krebs Cycle. This is the direct transfer of phosphate from a respiratory intermediate to ADP to produce ATP.
• Oxidative phosphorylation occurs in the electron transfer chain. This is the indirect linking of energy from phosphate to ADP to produce ATP involving energy from the hydrogen atoms that are carried on NAD and FAD. This is the most common mechanism for ATP production.