Cellular Respiration Stage 4: Electron Transport Chain Cellular respiration What?s the point? The point is to make ATP! ATP ATP accounting so far? Glycolysis ? 2 ATP Kreb?s cycle ? 2 ATP Life takes a lot of energy to run, need to extract more energy than 4 ATP! A working muscle recycles over 10 million ATPs per second There?s got to be a better way! I need a lot more ATP! There is a better way! Electron Transport Chain series of proteins built into inner mitochondrial membrane along cristae transport proteins & enzymes transport of electrons down ETC linked to pumping of H+ to create H+ gradient yields ~36 ATP from 1 glucose! only in presence of O2 (aerobic respiration) O2 That sounds more like it! Mitochondria Double membrane outer membrane inner membrane