AP Biology  convert glucose (6C) to 2 pyruvate (3C)  produces: 4 ATP & 2 NADH  consumes: 2 ATP  net: 2 ATP & 2 NADH glucose C-C-C-C-C-C P-C-C-C-C-C-C-P P-C-C-C C-C-C-P pyruvate C-C-C Overview ATP 2 ADP 2 ATP 4 ADP 4 NAD Pi2Pi 2P2P 2H2H P-C-C-C-P

AP Biology Cellular Respiration Stage 2 & 3: Oxidation of Pyruvate Krebs Cycle

AP Biology Cellular respiration

AP Biology intermembrane space inner membrane outer membrane matrix cristae Mitochondria mitocondrial DNA What cells would have a lot of mitochondria?

AP Biology Preparatory Steps to the Krebs: 2 Pyruvate C-C-C If oxygen is present in the organism… The two Pyruvate molecules enter the mitochondria

AP Biology Preparatory Steps to the Krebs: 2 Pyruvate C-C-C CO 2 Several reactions take place: 1. A carbon is taken out of each pyruvate, combine with Oxygens, creating 2 Carbon Dioxide molecules

AP Biology Preparatory Steps to the Krebs: Coenzyme A 2 Pyruvate C-C-C CO 2 NAD + 2.Electrons and Hydrogen are given up to turn 2 NAD molecules to NADH 3.Coenzyme A molecule is combined with each 2 carbon molecule

AP Biology Preparatory Steps to the Krebs: Coenzyme A 2 Pyruvate Acetyl CoA C-C-C C-C CO 2 NAD + The end result of these preparatory steps are 2 Acetyl CoA molecules Also made: 2 Carbon Dioxides, 2 NADH

AP Biology Tally 2- CO2 2- NADH ATP

AP Biology Tally 4- CO2 4- NADH ATP

AP Biology Tally 6- CO2 6- NADH ATP

AP Biology Tally 6- CO2 6- NADH 2- ATP ATP

AP Biology Tally 6- CO2 6- NADH 2- ATP 2- FADH2 ATP

AP Biology Tally 6- CO2 8- NADH 2- ATP 2- FADH2 ATP

AP Biology 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 I need a lot more ATP!

AP Biology Value of Krebs cycle?  If the yield is only 2 ATP then how was the Krebs cycle an adaptation for larger animals?  value of NADH & FADH 2  electron carriers & H carriers move energy  to be used in the Electron Transport Chain like $$ in the bank

AP Biology Electron Transport Chain  Double membrane  inner membrane  highly folded cristae  enzymes & transport proteins

AP Biology Electron Transport Chain Intermembrane space Mitochondrial matrix Inner mitochondrial membrane

AP Biology G3P Glycolysis Krebs cycle 8 NADH 2 FADH 2 Remember the Electron Carriers? 2 NADH Time to break open the piggybank! glucose

AP Biology Electrons flow downhill  Electrons move in steps from carrier to carrier downhill to oxygen  controlled release of energy Total Tally 10- NADH 4- ATP 2- FADH2

AP Biology Electrons flow downhill ETC also called Oxidation Phosphorylation  Each NADH yields ‘up to’ 3 ATP  Each FADH2 yields ‘up to’ 2 ATP  4 ATP already created  1 Glucose can yield 38 ATP Total Tally 10- NADH 4- ATP 2- FADH2