Cellular respiration

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

Cellular Respiration Stage 1: Glycolysis What?s the point? The point is to make ATP! ATP Glycolysis Breaking down glucose ?glyco ? lysis? (splitting sugar) ancient pathway which harvests energy where energy transfer first evolved transfer energy from organic molecules to ATP still is starting point for ALL cellular respiration but it?s inefficient generate only 2 ATP for every 1 glucose occurs in cytosol glucose ? ? ? ? ? pyruvate 2x 6C 3C In the cytosol? Why does that make evolutionary sense? That?s not enough ATP for me! Evolutionary perspective Prokaryotes first cells had no organelles Anaerobic atmosphere life on Earth first evolved without free oxygen (O2) in atmosphere energy had to be captured from organic molecules in absence of O2