LECTURE 4: Cellular Respiration TODAY’S OBJECTIVES: Describe structure of mitochondria Summarize 3 steps of Cellular Respiration and identify where ATP is made

What are the inputs/outputs of cellular respiration? Carbon Dioxide Water ATP INPUTS: Oxygen Glucose

What is the Structure of Mitochondria?

Generation of ATP Three stage process 1. Glucose is broken down into pyruvate Glycolysis in cytoplasm 2. Pyruvate broken down to make reducing molecules Krebs cycle in mitochondria matrix 3. Use electron transport chain to make ATP ETC makes H+ gradient which generates ATP Occurs on innermembrane

Aerobic Respiration 2 ATP 2 NADH Stage 1 - Glycolysis

For each glucose used up Glucose  2 Pyruvate 6 C’s 2 x 3 C’s For each glucose used up 2 ATP (used 2 ATP, made 4 ATP) 2 NADH 2 pyruvates

4 CO2 Aerobic Respiration Stage 2 - Krebs Cycle 2 acetyl CoA 2 NADH 6 FADH2 2 GTP Stage 2 - Krebs Cycle

End Result of Glycolysis + Krebs Cycle Glucose  2 Pyruvate  6 CO2 For each glucose 2 ATP (used 2 ATP, made 4 ATP) 2 NADH (cytoplasm) 2 NADH (in mitochondria) 6 NADH (Krebs) 2 FADH2 (Krebs)

Stage 3 - Electron Transport Chain Aerobic Respiration H+ + O2 8 (10) NADH e- 2 FADH2 H2O H+ gradient ATP Stage 3 - Electron Transport Chain

3RD STAGE ETC Electron Transport Chain (ETC) NADH / FADH2 molecules are used as electron donors They release an electron, an electron acceptor ‘accepts’ electrons Oxygen is the last acceptor – creates H2O This pushes H+ across the membrane, creating a gradient These H+ than go back across the membrane through an ATP synthase This makes ATP NADH gives 3 ATP - FADH2 gives 2 ATP

NADH gives 3 ATP - FADH2 gives 2 ATP O2 + 2H+ H2O ADP ATP NADH gives 3 ATP - FADH2 gives 2 ATP

H+ ions increase in intermembrane space

ATP Synthase Hydrogen ions get pumped down pump Energy turns turbines to bind phosphate group to ADP to form ATP

End Result of Glycolysis + Krebs Cycle Glucose  2 Pyruvate  6 CO2 For each glucose 2 ATP (used 2 ATP, made 4 ATP) 2 NADH (cytoplasm) 2 NADH (in mitochondria) 6 NADH (Krebs) 2 FADH2 (Krebs) In ETC NADH  6H+ FADH2  4H+ Each 2H+ makes 1 ATP

36 ATP For each glucose 2 ATP (used 2 ATP, made 4 ATP) 2 NADH (cytoplasm) =6 ATP 2 NADH (in mitochondria)= 6 ATP 6 NADH (Krebs)= 18 ATP 2 FADH2 (Krebs)= 4 ATP