The Electron transport chain is the last step of cellular respiration. In this stage, energy from NADH and FADH2, which result from the Krebs cycle, is transferred to ATP .
Remember glycolysis has already produced 2 ATP and Krebs cycle another two ATP molecules.
High energy electrons are released then from NADH and FADH2 and they move along electron transport chains and as this happens, some of their energy is captured . This energy is transferred to form as many as 34 more molecules of ATP. All told, 36 to 38 ATP molecules are produced from just one molecule of glucose in the process of aerobic respiration.
