What is the respiratory chain?

Metabolic chain not physical, composed of four enzymatic complexes, proteins of this chain act in a sequential manner although not covalently bonded. Among them there are proteins such as cytochromes (hemoproteins) and flavoproteins (FAD with proteins) involved in oxidation reduction reactions. respiratory chain performs cell respiration by oxidizing the coenzymes that are reduced during glycolysis, Krebs cycle, beta-oxidation. Cell respiration generates a proton gradient during the transfer of electrons from coenzymes to O2.