Oxidative phosphorylation. It is the synthesis of ATP molecules from ADP and iP (inorganic phosphate) during aerobic respiration. ADP + i P + energy ----> ATP

The energy is evolved during electron transport chain and H⁺ shift from the outer chamber of mitochondria into inner chamber through F₀-F₁ particles. When electron is passing through F1 particle or head of oxysome then its energy is taken by ADP + iP to form ATP. Therefore oxysome acts as ATPase.

When one molecule of NADH is oxidized then 3 ATP molecules are produced. When one molecule of FADH₂ in oxidized, 2 ATP molecule are produced.

In eucaryotic cells, one molecule of glucose on oxidation produces 36 ATP molecules.

During aerobic oxidation in prokaryotic cell, of one glucose molecule 38 ATP molecules are produced. ATP’s are the energy currency of the cell.