How does oxidative phosphorylation work in respiration

Reduced NAD/FAD from previous stages of respiration (glycolysis, link reaction, Krebs cycle) relocate from the mitochondrial matrix to the inner mitochondrial membrane. At this point they are oxidised, losing their extra electron to proteins (cytochrome proteins) which are embedded in the inner membrane of the mitochondria. The NAD/FAD are then shuttled back to the mitochondrial matrix where they can be reused in earlier stages of respiration. The electron that was lost then passes down a series of cytochrome proteins (known as the ELECTRON TRANSPORT CHAIN or ETC), and as it does releases energy which is used to transport free H+ ions from the mitochondrial matrix into the inter membrane space. This creates an H+ concentration gradient across the inner mitochondrial membrane, with a higher concentration of H+ in the inter membrane space than in the matrix. H+ ions then move down this concentration gradient and back into the matrix through ATP synthase. By moving through this protein, it is activated and can combine ADP and an inorganic phosphate molecule to form ATP. Finally, once the electron reaches the end of the ETC and combines with oxygen, reducing it. This oxygen can then combine with H+, which has moved into the matrix, and form water.