1. Chapter 9 Cellular Respiration

2. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production is the benefit for the cell

3. B.Redox Reactions: Transfer electrons from one reactant to another reactant 1.Oxidation: Substance loses electrons (Na) 2.Reduction: Substance gains electrons (Cl) 3.Electronegativity: An atoms ability to attract electrons to itself (Cl) 4.Energy is released when an electron changes location.

4. C.Redox Reactions when electrons are shared. 1.Some redox reactions change the degree to which electrons are shared. 2.Methane Example CH 4 H H H H C OO O O O C HH Methane (reducing agent) Oxygen (oxidizing agent) Carbon dioxideWater + 2O 2 CO 2 + Energy + 2 H 2 O becomes oxidized becomes reduced Reactants Products Figure 9.3

5. 3.Cellular respiration is similar. a)C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O b)Hydrogens are transferred to Oxygen c)More importantly, hydrogen’s electrons move away from it and closer to oxygen d)Much energy is released in this motion

6. D. NAD + and Energy harvest from e - 1.Hydrogen does not immediately join Oxygen to form water. (C 6 H 12 O 6 + O 2  CO 2 H 2 O) 2.NAD + : (Nicotinamide adenine dinucleotide) a)Allows e - energy to be harvested slowly. (a) Uncontrolled reaction Free energy, G H2OH2O Explosive release of heat and light energy Figure 9.5 A H 2 + 1 / 2 O 2

7. 3.NAD + : (Nicotinamide adenine dinucleotide) a)Allows e - energy to be harvested slowly. i.NAD + strips 2 e - s from glucose ii.Along with them come 2 hydrogens (NADH + H + ) iii.Very little energy is lost from the electrons here. iv.The 2e - s can be passed to other molecules to release E. to make ATP 2H + O H2OH2O ATP

8. E.The Stages of Cellular RespirationThe Stages of Cellular Respiration 1.Glycolysis »Glucose (6C)  Pyruvate(3C) »in Cytoplasm 2.Citric Acid Cycle »products of glycolysis broken down to CO 2 »inside mitochondria 3.Electron Transport: (Oxidative Phosphorylation) »High Energy Electrons from 1 and 2 passed down a chain of molecules to produce H 2 O. »The energy released in the chain is used to make ATP via (oxidative phosphorylation)

9. F.Substrate-Level Phosphorylation: Adding a phosphate to ADP to make ATP 1.phosphate from an organic molecule rather than free floating. Figure 9.7 Enzyme ATP ADP Product Substrate P +

10. CH 2 O P Glucose-6-phosphate Glyceraldehyde-3-phosphate II. Glycolysis C Glucose Hexokinase 1 P A P P P A P P O CH 2 O P C Fructose-6-phosphate Phosphoglucoisomerase 2 P O CH 2 P O O Fructose-1,6-bisphosphate Phosphofructokinase 3 C P O C=O C P CH 2 O C=O C Aldolase 4 Isomerase 5 Glyceraldehyde-3-phosphate P CH 2 O C=O C Dihydroxyacetone Phosphate

11. P CH 2 O C=O C Glyceraldehyde-3-phosphate P CH 2 O C=O C P O 1,3-Bisphosphoglycerate Triose phosphate dehydrogenase 6 P CH 2 O C=O C 3-Phosphoglycerate P C O C=O C Phosphoenolpyruvate C C=O Pyruvate P A P P P Phosphoglycerokinase 7 P A P P P C O C=O C 2-Phosphoglycerate Phosphoglyceromutase 8 Enolase 9 Pyruvate Kinase 10

12. III.Citric Acid Cycle A.Preparation 1.Pyruvate enters mitochondria 2.If oxygen is present cell resp. proceeds. 3.Acetyl CoA produced 1.CO 2 removed 2.Oxidation by NAD + 3.Coenzyme A attached to remaining two carbons. 4.Acetyl CoA enters the Citric Acid Cycle Coenzyme A C C=O Pyruvate O-O- C C=O CoA NAD + NADH + H + CO 2

13. ATP 2 CO 2 3 NAD + 3 NADH + 3 H + ADP + P i FAD FADH 2 Citric acid cycle CoA Acetyle CoA NADH + 3 H + CoA CO 2 Pyruvate (from glycolysis, 2 molecules per glucose) ATP Glycolysis Citric acid cycle Oxidative phosphorylatio n Figure 9.11

14. C C=O CoA Acetyl CoA COO - O=C C COO - Oxaloacetate COO - HO-C C COO - C Citrate COO - C C HO-C Isocitrate COO - C C O=C α-Ketogluterate C C COO - O=C CoA Succinyl CoA C C COO - Succinate C C COO - Fumarate C HO-C COO - Malate COO - O=C C COO - Oxaloacetate H2OH2O H2OH2O CO 2 NAD + NADH + H + CO 2 NAD + NADH + H + CoA A P P P P A P P FAD FADH 2 H2OH2O NAD + NADH + H +

15. Acetyl CoA NADH Oxaloacetate Citrate Malate Fumarate Succinate Succinyl CoA  -Ketoglutarate Isocitrate Citric acid cycle SCoA SH NADH FADH 2 FAD GTP GDP NAD + ADP P i NAD + CO 2 CoA SH CoA SH CoA S H2OH2O + H + H2OH2O C CH 3 O OCCOO – CH 2 COO – CH 2 HO C COO – CH 2 COO – CH 2 HCCOO – HOCH COO – CH CH 2 COO – HO COO – CH HC COO – CH 2 COO – CH 2 CO COO – CH 2 CO COO – 1 2 3 4 5 6 7 8 Glycolysis Oxidative phosphorylation NAD + + H + ATP Citric acid cycle Figure 9.12 Results of CAC (one turn) ATP = NADH = FADH 2 = CO 2 = 1 3 1 2

16. C C=O CoA Acetyl CoA COO - O=C C COO - Oxaloacetate COO - HO-C C COO - C Citrate COO - C C HO-C Isocitrate COO - C C O=C α-Ketogluterate C C COO - O=C CoA Succinyl CoA C C COO - Succinate C C COO - Fumarate C HO-C COO - Malate CoA H2OH2O H2OH2O CO 2 NAD + NADH + H + NADH + H + NADH + H + FAD FADH 2 P A P P P A P P

17. IV. Electron Transport, Oxidative Phosphorylation and Chemiosmosis A.Structure of Mitochondria Matrix: Juice. Site of Citric acid cycle. A. Cristae: Folds in the inner memebrane. Site of electron transport. B. Intermembrane space:

18. B.Electron Transport Overview: The following animation and diagram are an overview of the process. Definitions will follow. - Oxidative Phosphorilation: ATP production using energy derived from redox reactions.

19. NADH Outer Membrane H+H+ Inner Membrane Intermembrane Space Matrix H+H+ H+H+ FADH 2 FAD OH2OH2O Complex 1 Complex 2 Complex 3 Complex 4 NAD + ADP P ATP ATP Synthase

20. ubiquinone NADH Outer Membrane H+H+ Inner Membrane Intermembrane Space Matrix H+H+ H+H+ O H2OH2O Complex 1 Complex 2 Complex 3 Complex 4 NAD + ADP + P ATP 2e - H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ ATP Synthase

21. ubiquinone FAD Outer Membrane H+H+ Inner Membrane Intermembrane Space Matrix H+H+ O H2OH2O Complex 1 Complex 2 Complex 3 Complex 4 FADH 2 ADP + P ATP 2e - H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ ATP Synthase 2e -

22. C.Chemiosmosis:Chemiosmosis: 1.The process of electron transport makes no ATP directly. 2.Electron transport creates a H + gradient. a.Results in high H + amounts in the intermembrane space. b.This is like water build up behind a dam. It has a lot of potential energy. c.Proton-motive force: The name given to the gradient. i.The force tries to push the protons back across the membrane to reach equilibrium. d.Chemiosmosis: Using energy stored in the H + gradient across a membrane to synthesize ATP.

23. D.ATP Synthase: The enzyme that makes the ATPATP Synthase: 1.ATP synthase is the only place protons can go back through the membraneATP synthase is the only place protons can go back through the membrane INTERMEMBRANE SPACE H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ P i + ADP ATP A rotor within the membrane spins clockwise when H + flows past it down the H + gradient. A stator anchored in the membrane holds the knob stationary. A rod (for “stalk”) extending into the knob also spins, activating catalytic sites in the knob. Three catalytic sites in the stationary knob join inorganic Phosphate to ADP to make ATP. MITOCHONDRIAL MATRIX Figure 9.14

24. E.Energy Totals for Cellular Respiration 1. ATP Formed –Glycolysis = 2 –Pyruvate Oxydation = 0 –CAC = 2 2. NADH Generated –Glycolysis = 2 –Pyruvate OXydation = 2 –CAC = 6 –ATP/ NADH = 3 –Total ATP from all NADH = 30 3. FADH 2 Generated –Glycolysis = 0 –Pyruvate Oxydation = 0 –CAC= 2 –ATP generated per FADH 2­ = 2 –Total ATP from FADH 2 = 4 Total ATP from catabolism of one glucose = 38 sometimes 36

25. V.Fermentation: Production of ATP from glucose when no oxygen is present (Anaerobic) A. General Rules: 1.Cellular respiration can’t happen w/o oxygen 2. Fermentation allows us to make ATP anyway. 3. Glycolysis makes 2 ATP by subtrate level phosphorilation. a. If done rapidly this could be enough to get by b. The limiting factor is the amount of available NAD + available. 4. Fermentation allows glycolysis to continue by oxidizing the NADH for reuse.

26. B. Types: 1. Alcohol Fermentation: Pyruvate is converted to ethanol. –Often used by bacteria and yeast –Step 1: Pyruvate releases 2CO 2  Acetaldehyde –Step 2: Acetaldehyde oxidizes NADH  ethanol and NAD + 2 ADP + 2 P1P1 2 ATP Glycolysis Glucose 2 NAD + 2 NADH 2 Pyruvate 2 Acetaldehyde 2 Ethanol (a) Alcohol fermentation 2 ADP + 2 P1P1 2 ATP Glycolysis Glucose 2 NAD + 2 NADH 2 Lactate (b) Lactic acid fermentation H H OH CH 3 C O – O C CO CH 3 H CO O–O– CO CO O CO C OHH CH 3 CO 2 2 Figure 9.17

27. 2 ADP + 2 P1P1 2 ATP Glycolysis Glucose 2 NAD + 2 NADH 2 Pyruvate 2 Acetaldehyde 2 Ethanol (a) Alcohol fermentation 2 ADP + 2 P1P1 2 ATP Glycolysis Glucose 2 NAD + 2 NADH 2 Lactate (b) Lactic acid fermentation H H OH CH 3 C O – O C CO CH 3 H CO O–O– CO CO O CO C OHH CH 3 CO 2 2 Figure 9.17 2. Lactic Acid Fermentation 1. Happens in human muscles as well as bacteria that make cheese. 2. One Step: Pyruvate oxidizes NADH  NAD + + Lactic Acid.

28. c. Comparing Fermentation and Cellular Respiration Cellular Respiration 1.Aerobic 2.38 ATP produced 3.NADH oxidized to produce H 2 0 Fermentation 1.Anaerobic 2.2 ATP produced 3.NADH oxidized to make ethanol or lactate