1. Chapter 9 Cellular Respiration: Harvesting Chemical Energy

2. Is this a process of turning food into energy?

3. Rs - Equation C 6 H 12 O 6 + 6 O 2 6 CO 2 + 6 H 2 O and energy The energy is released from the chemical bonds in the complex organic molecules.

4. Respiration - Preview u The process of releasing Energy from food. u Food - Stored Energy in chemical bonds. u ATP - Useable Energy for cell work.

6. Focus of Chapter 1. Purpose - what is the reaction suppose to do? 2. Location - where is it at? 3. Requirements - what is needed to make it run? 4. Products - what does it produce?

7. Oxidation - definitions u Loss of electrons. u Loss of energy. u Loss of Hydrogens from Carbons.

8. Reduction - definitions u Gain of electrons. u Gain of energy. u Gain of Hydrogens to Carbons. Comment - be careful not to use “reduction” in lay terms.

9. Redox reactions

10. u Reactions are usually paired or linked together. u Look for these links as we study Rs. u Many of the reactions will be done by phosphorylation

11. Phosphorylation u Adding a phosphate group to a molecule. u The phosphate group adds “energy” to the molecule for chemical reactions.

12. Phosphorylation

13. Cell Respiration - parts 1. Glycolysis 2. Krebs Cycle 3. Electron Transport Chain

14. Glycolysis u Glyco- glucose. u -lysis: to split u Universal step in all Rs types. u Likely to earliest type of cell energy processes.

15. Glycolysis u Function - To split glucose and produce NADH and ATP. u Location - Cytoplasm.

17. Electron Carrier Compounds u Molecules that transport or shuttle electrons within the cell. u Exist it two forms: u Oxidized (ox) u Reduced (red)

18. NAD u Nicotinamide Adenine Dinucleotide NAD + + 2 e - NADH NAD + = oxidized form NADH = reduced form

20. Glycolysis -Requirements u Glucose u 2 ATP u 4 ADP u 2 NAD +

21. Glycolysis - Products u 2 Pyruvic Acids (a 3C acid) u 2 ADP u 4 ATP u 2 NADH

22. Net Result u 2 ATP per glucose u 2 NADH

23. Movie

25. Energy Investment Phase

26. Energy Harvest Phase

27. Krebs Cycle u Also called: u Citric Acid Cycle u Tricarboxylic Acid Cycle

28. Krebs Cycle u Function: Oxidize pyruvic acid to CO 2 u Produce NADH and FADH 2 u Location: Mitochondria matrix

29. Movie

30. Formation of Acetyl CoA

31. Krebs Cycle -Requirements u Pyruvic acid (3C acid) u Coenzyme A u 4 NAD + u 1 ADP u 1 FAD u Double this list for each glucose.

32. Krebs Cycle - Products u 3 CO 2 u Acetyl CoA u 4 NADH u 1 ATP u 1 FADH 2 u Double this list for each glucose.

35. Krebs Cycle u Produces most of the cell's energy in the form of NADH and FADH 2 u Does NOT require O 2

36. Comment u The ATPs produced directly in Krebs Cycle and in Glycolysis are by: u Substrate-level phosphorylation u The Pi group is transferred from a substrate to ADP.

37. Electron Transport Chain u ETC or Electron Transport System (ETS). u A collection of proteins that are structurally linked into units.

38. ETC u Uses sets of Cytochromes, Fe containing proteins to pass electrons. u The Cytochromes alternate between RED and OX forms and pass electrons down to O 2

40. ETC u Function: Convert NADH and FADH 2 into ATP. u Location: Mitochondria cristae.

41. ETC - Requirements u NADH or FADH 2 u ADP uO2uO2

42. ETC - Products u NAD + and FAD u ATP uH2OuH2O

43. Movie

44. ETC - ATP Yields u Each NADH -- 3 ATP u Each FADH 2 -- 2 ATP

45. Chemiosmotic Hypothesis u ETC energy is used to move H + (protons) across the cristae membrane. u ATP is generated as the H + diffuse back into the matrix.

47. ATP Synthase u Uses the flow of H + to make ATP. u Works like an ion pump in reverse, or like a waterwheel under the flow of H + “water”.

49. Alcoholic Fermentation u Done by yeast, a kind of fungus.

51. Movie

52. Alcoholic Fermentation u Uses only Glycolysis. u An incomplete oxidation - energy is still left in the products (alcohol). u Does NOT require O 2 u Produces ATP when O 2 is not available.

54. Lactic Acid Fermentation u Uses only Glycolysis. u An incomplete oxidation - energy is still left in the products (lactic acid). u Does NOT require O 2 u Produces ATP when O 2 is not available.

55. Movie

57. Lactic Acid Fermentation u Done by human muscle cells under oxygen debt. u Lactic Acid is a toxin and causes soreness and stiffness in muscles.

58. Fermentation - Summary u Way of using up NADH so Glycolysis can still run. u Provides ATP to a cell even when O 2 is absent.

60. Aerobic vs Anaerobic u Aerobic - Rs with O 2 u Anaerobic - Rs without O 2 u Aerobic - All three Rs steps. u Anaerobic - Glycolysis only.

61. Strict vs. Facultative u Strict - can only do Rs this one way. u Facultative - can switch Rs types depending on O 2 availability. Ex - yeast

62. Question u Since yeast can do both aerobic and anaerobic Rs, which is the better process if given a choice? u Check the ATP yields from both processes.

63. ATP yields by Rs type u Anaerobic - Glycolysis only Gets 2 ATPs per glucose. u Aerobic - Glycolysis, Krebs, and ETC. Generates many more ATPs per glucose.

64. Aerobic ATP yield u Glycolysis - 2 ATPS, 2 NADHs u Krebs - 2 ATPS, 8 NADHs, 2 FADH 2 u Each NADH = 3 ATP u Each FADH 2 = 2 ATP

65. ATP Sum u 10 NADH x 3 = 30 ATPs u 2 FADH 2 x 2 = 4 ATPs u 2 ATPs (Gly) = 2 ATPs u 2 ATPs (Krebs) = 2 ATPs u Max = 38 ATPs per glucose

66. However... u Some energy is used in shuttling the NADH from Glycolysis into the mitochondria. u Actual ATP yield ~ 36/glucose

67. Yeast u Would rather do aerobic Rs; it has 18x more energy per glucose. u But, anaerobic will keep you alive if oxygen is not present.

68. Importance of Rs u Convert food to ATP. u Provides materials for use in other cellular pathways.

69. Other Importances of Respiration u Alcohol Industry - almost every society has a fermented beverage. u Baking Industry - many breads use yeast to provide bubbles to raise the dough.

70. Matching Sugar Cane Gin Barley Saki Grapes Tequila Juniper Cones Vodka Agave Leaves Beer Rice Wine Potatoes Rum

71. Question u Why is the alcohol content of wine always around 12-14%? u Alcohol is toxic and kills the yeast at high concentrations.

72. Swiss Cheese u Holes are bubbles of CO 2 from fermentation.

73. Summary u Know the 3 main reactions of Rs and the 4 required items for each. u Appreciate the importances of Rs.

74. Rs Lab Report u Use data sheet for the three temperatures to make the graph.  Show changes as  mmHg. This will give you a positive slope.

75. Lab Report u Answer the 9 questions. u On #5, use the entire 30 minutes for calculating the rate.

76. Osmosis Lab Report u Table 1 & 7 questions u Graph dialysis bag results u Use class data set u Use a best-fit line or a trendline u Answer the 4 questions

77. u Graph potato results u Use class data set u Use a best-fit line or a trendline u Answer the 7 questions u Assume the temperature was 22 o C