Slide 1 / 165. Respiration & Photosynthesis

Transcription

1 Slide 1 / 165 Respiration & Photosynthesis

2 Slide 2 / 165 Energy and Life Usually, energy flows into ecosystems as light from the sun and leaves as heat. Photosynthesis uses the energy in sunlight to generate oxygen and glucose; while trapping carbon. Cellular respiration uses that glucose to generate ATP, which supplies useable energy for cells while releasing carbon and absorbing oxygen. Cells use ATP to generate. The overall effect is for solar energy to be transformed to energy that is used by life; and then finally heat. Much of that heat is then radiated away from Earth as infrared radiation.

3 Slide 3 / 165 Energy and Life O C O Fe O Abiotic Chemicals N O HEAT Solar Energy HEAT (CO 2, O 2, N, minerals) HEAT decomposers (bacteria, fungi) Producers (plants) HEAT HEAT consumers (herbivores, carnivores)

4 Slide 4 / 165 The Production of ATP Catabolic Pathways Recall that catabolism is that aspect of metabolism involved in breaking down molecules to release energy. Cellular respiration is a catabolic pathway that consumes oxygen and organic molecules and yields ATP. Carbohydrates, fats, and proteins can all fuel cellular respiration. We'll look first at the simplest case, the breakdown of the sugar - glucose.

5 Slide 5 / 165 The Production of ATP Catabolic Pathways The breakdown of organic molecules is exergonic, it releases energy. Catabolic pathways yield energy by oxidizing organic fuels. This is the balanced chemical reaction, when O 2 is available, for the combustion of glucose to provide energy to cells: C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + ATP

6 Slide 6 / 165 Combustion Reactions The shuttle boosters use the rapid combustion of fuel to power 4.4 billion pounds away from Earth. While the chemical process of cellular respiration is similar to this powerful reaction, cells must use a much more carefully-controlled process to get useable energy from the combustion of glucose.

7 Slide 7 / 165 Cellular Respiration There are two types of cellular respiration: Anaerobic - which occurs without the use of oxygen Aerobic - which requires the use of oxygen Both forms share the same first step: Glycolysis So let's talk about that first, then we can discuss the two types of respiration that follow from that first stage But before doing that we have to learn about two molecules that are essential to respiration

8 Slide 8 / 165 NAD + and FAD The molecules NAD + and FAD are used to store, and later release, energy during respiration; they are key to respiration. Each molecules has two forms, each form stores a different amount of energy. So moving between those two forms either stores chemical potential energy or releases it. Here are the reactions: NAD + + 2H + + 2e - + Energy NADH + H + FAD + 2H + + 2e - + Energy FADH 2 The double arrows indicate that each reaction is reversible, they can proceed in either direction. When the reaction goes to the right, energy is stored. When it goes to the left, energy is released

9 Slide 9 / 165 NAD + and FAD NAD + + 2H + + 2e - + Energy NADH + H + FAD + 2H + + 2e - + Energy FADH 2 The amount of energy that is useable when the reaction goes to the left, depends on the availability of O 2. Without the presence of O 2, the energy stored in NADH and FADH 2 cannot be used to make ATP. If O 2 is present, 1 NADH stores enough energy to create about 3 ATPs 1 FADH 2 stores enough energy to make about 2 ATPs

10 Slide 10 / Anaerobic processes. A B C D require the use of oxygen do not require the use of oxygen require the use of hydrogen do not require the use of hydrogen

11 Slide 11 / Aerobic processes. A B C D require the use of oxygen do not require the use of oxygen require the use of hydrogen do not require the use of hydrogen

12 Slide 12 / NADH is converted to NAD +. During this process,. A B C energy is released energy is stored no energy is stored or released

13 Slide 13 / NAD + is converted to NADH. During this process,. A B C energy is released energy is stored no energy is released or stored

14 Slide 14 / FAD is converted to FADH 2. During this process,. A B C energy is released energy is stored no energy is released or stored

15 Slide 15 / FADH 2 is converted to FAD. During this process,. A B C energy is released energy is stored no energy is released or stored

16 Slide 16 / 165 Reduction and Oxidation NAD + + 2H + + 2e - + Energy NADH + H + FAD + 2H + + 2e - + Energy FADH 2 When we go from left to right we are adding electrons to a molecule. That is called reducing the molecule, or the process of reduction. Going from right to left, we are taking electrons from a molecule. That is called oxidizing the molecule, or the process of oxidation.

17 Slide 17 / 165 Oxidation The reason for the term oxidation is that this is the effect that oxygen usually has: it takes electrons from a molecule, oxidizing the molecule The rusting of iron is an example of oxidation: oxygen is taking electrons from the metal, oxidizing it. 4 Fe + 3 O 2 2 Fe 2 O 3

18 Slide 18 / 165 Reduction and Oxydation Since it doesn't seem right that adding electrons is called "reduction"; here's a way to remember these two terms. LEO says GER Losing Electrons is Oxidation Gaining Electrons is Reduction

19 Slide 19 / When a molecule is oxidized, electrons are removed from it. True False

20 Slide 20 / When a molecule is reduced, electrons are removed from it. True False

21 Slide 21 / 165 Glycolysis This is the first stage of both anaerobic and aerobic respiration. It involves the breakdown of glucose, a 6 carbon sugar, into 2 molecules of pyruvate, a 3 carbon sugar. 2 NAD + C 6 H 12 O 6 (Glucose) 2 ATP Glycolysis means the splitting of glucose Gycolysis 2 NADH 4 ATP 2 C 3 H 4 O 3 (Pyruvate)

22 Slide 22 / 165 Glycolysis This is the first stage of both anaerobic and aerobic respiration. It involves the breakdown of glucose, a 6 carbon sugar, into 2 molecules of pyruvate, a 3 carbon sugar. 2 NAD + C 6 H 12 O 6 (Glucose) 2 ATP Some ATP is needed to start the process, but the net result is : Gycolysis 2 NADH 4 ATP 2 C 3 H 4 O 3 (Pyruvate)

23 Slide 23 / 165 Glycolysis This is the first stage of both anaerobic and aerobic respiration. It involves the breakdown of glucose, a 6 carbon sugar, into 2 molecules of pyruvate, a 3 carbon sugar. 2 NAD + C 6 H 12 O 6 (Glucose) 2 ATP Some ATP is needed to start the process, but the net result is : 2 NADH Gycolysis 2 C 3 H 4 O 3 (Pyruvate) 4 ATP a net of 2 ATPs are formed along with 2 NADHs and the 2 pryuvates. note: 2 ATP go into the reaction, 4 come out of the reaction - which gives the NET of 2

24 Slide 24 / 165 Fermentation Without O 2, the energy stored in NADH 2 and pyruvate can't be used. The net energy gain of anaerobic respiration is just 2 ATPs. (Remember 2 were invested and 4 were produced, netting 2) However, the Pyruvate still needs to be cleared from the cell, and the NADH converted back to NAD + to begin another cycle. The process of doing this is called fermentation.

25 Slide 25 / The process of glylcolyis requires oxygen. True False

26 Slide 26 / 165 Fermentation Fermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule. 2 NADH 2 C 3 H 4 O 3 (Pyruvate) 2 NAD + Lactic Acid Fermentation Fermentation OR Ethanol Fermentation 2 Lactic Acid CO 2 & 2 Ethanol

27 Slide 27 / 165 Fermentation Fermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule. 1 glucose molecule had yielded 2 ATPs, 2 Pyruvates and 2 NADHs. That is the input to the fermentation stage of anaerobic respiration. 2 NADH 2 NAD + Lactic Acid Fermentation 2 C 3 H 4 O 3 (Pyruvate) Fermentation OR Ethanol Fermentation 2 Lactic Acid CO 2 & 2 Ethanol

28 Slide 28 / 165 Fermentation Fermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule. 1 glucose molecule had yielded 2 ATPs, 2 Pyruvates and 2 NADHs. That is the input to the fermentation stage of anaerobic respiration. The pyruvates and NADHs are fermented into 2 NAD + and either Lactic Acid or 2 NADH 2 NAD + Lactic Acid Fermentation 2 C 3 H 4 O 3 (Pyruvate) 2 Lactic Acid Fermentation OR Ethanol Fermentation CO 2 & 2 Ethanol

29 Slide 29 / 165 Fermentation Fermentation breaks down the products of glycolysis so that glycolysis can be repeated with another glucose molecule. 1 glucose molecule had yielded 2 ATPs, 2 Pyruvates and 2 NADHs. That is the input to the fermentation stage of anaerobic respiration. The pyruvates and NADHs are fermented into 2 NAD + and either Lactic Acid or CO 2 & Ethanol. 2 NADH 2 NAD + Lactic Acid Fermentation 2 C 3 H 4 O 3 (Pyruvate) 2 Lactic Acid Fermentation OR Ethanol Fermentation CO 2 & 2 Ethanol

30 Slide 30 / 165 Anaerobic Respiration The result of the combined steps of glycolysis and fermentation is: The input is 1 Glucose + 2 ATP molecules The output is 4 ATP molecules (for a net gain of 2 ATP's) In addition, Lactic Acid fermentation results in lactic acid Ethanol fermentation results in ethanol and CO 2

31 Slide 31 / 165 Anaerobic Respiration For about the first 2.0 BY of life on Earth, before oxygen became prevalent in the atmosphere about 2.5 BYA, there was only anaerobic respiration. But even now, it is the only means of cellular respiration in oxygen-poor environments.

32 Slide 32 / 165 Examples of Anaerobic Respiration Anaerobic organisms live in oxygen-poor environments and rely on glycolysis and fermentation for energy. The alcohol in wine, beer, etc. results from yeast undergoing ethanol fermentation. Bread rises due to the release of CO 2 bubbles by fermenting yeast. Your muscles burn after a strenuous workout because they can't get enough O 2, so they perform Lactic Acid Fermentation. Lactic acid results in soreness.

33 Slide 33 / 165 Alcohol Fermentation The final product is beer Breweries force yeast to do alcohol fermentation by supplying them with food called mash (hops, barley) while at the same time depriving the yeast of oxygen by filling airtight containers with water.

34 Slide 34 / 165 Lactic Acid Fermentation 2005 was the closest finish in the history of the NYC Marathon They had run 26.2 miles, stride for stride and were tied. Both men began to sprint to the finish. Paul Tergat vs. Hendrick Ramaala

35 Slide 35 / 165 Lactic Acid Fermentation Paul Teragat won by less than 1 second! What made the difference? How did he manage to beat his opponent?

36 Slide 36 / 165 Lactic Acid Fermentation When runners run for long distances they "keep pace", which means their cells never use more oxygen than can be replenished in muscle cells. When sprinting, oxygen runs out and lactic acid fermentation takes over in an attempt to make ATP without oxygen.

37 Slide 37 / 165 Lactic Acid Fermentation Lactic acid build up causes muscles to burn. Both runners were equally matched for cellular respiration but Tergat's muscles were able to withstand the pain of lactic acid fermentation better than Henrick's.

38 Slide 38 / The two types of fermentation are called A B C D Alcoholic and Aerobic. Aerobic and Anaerobic. Ethanol and Lactic Acid. Lactic acid and Anaerobic.

39 11 Alcoholic fermentation occurs in Slide 39 / 165 A B C D E humans yeast aerobic bateria none of the above all of the above

40 Slide 40 / The starting molecule for glycolysis is. A B C D ADP pyruvic acid citric acid glucose

41 Slide 41 / Glycolysis requires. A an energy input B oxygen C hours to produce many ATP molecules D NADP +

42 Slide 42 / How many ATP molecules are needed as input for glycolysis to proceed on 2 glucose molecules?

43 Slide 43 / How many ATP molecules are needed as input for glycolysis to proceed on 7 Glucose molecules?

44 Slide 44 / How many net ATP molecules are generated by the glycolysis of 9 glucose molecules?

45 Slide 45 / How many pyruvate molecules are generated by the glycolysis of 4 glucose molecules?

46 Slide 46 / What element was missing from the atmosphere of early Earth, when glycolysis and fermentation was the only stage of cellular respiration? A B C D E F Hydrogen Oxygen Mercury Nitrogen None of the Above All of the above

47 Slide 47 / What is a possible product of glycolysis and/or fermentation? A Alcohol B CO 2 C Pyruvate D Lactic Acid E None of the Above F All of the above

48 Slide 48 / 165 Oxygen Revolution For the first 2.0 BY of life on Earth, anaerobic respiration was the only means of obtaining energy from food. But then, the Oxygen Revolution occurred about 2.5 BYA, flooding the planet with oxygen. This led to made much more energy available to life, enabling the much more complex food chains we see today.

49 Slide 49 / 165 Similarities between Bacteria and Muscles Some bacteria, called facultative bacteria, after the glycolysis stage, can either go on to fermentation or, if O 2 is available, aerobic respiration. Your muscles do that as well: that's the difference between aerobic workouts and anaerobic workouts.

50 Slide 50 / 165 Aerobic vs. Anaerobic Respiration The big difference is that for each glucose molecule aerobic respiration yields 36 to 38 ATPs anaerobic respiration yields only 2 ATPs

51 Slide 51 / 165 The Stages of Aerobic Respiration Aerobic respiration consists of four stages: Glycolysis The Pyruvate Dehydrogenase Complex (PDC) The Citric Acid Cycle Oxidative Phosphorylation

52 Slide 52 / 165 The Stages of Aerobic Respiration Glycolysis The Pyruvate Dehydrogenase Complex (PDC) The Citric Acid Cycle Oxidative Phosphorylation The first stage, glycolysis, is the exactly the same as it is in the first stage of anaerobic respiration. Glycolysis first breaks down glucose into two molecules of pyruvate (pyruvic acid)

53 Slide 53 / 165 The Stages of Aerobic Respiration Glycolysis The Pyruvate Dehydrogenase Complex (PDC) The Citric Acid Cycle Oxidative Phosphorylation Pyruvate Dehydrogenase Complex (PDC) converts the 3- carbon pyruvate into a 2-carbon molecule that can be used in the Citric Acid Cycle.

54 Slide 54 / 165 The Stages of Aerobic Respiration Glycolysis The Pyruvate Dehydrogenase Complex (PDC) The Citric Acid Cycle Oxidative Phosphorylation The Citric Acid Cycle completes the breakdown of glucose, starting with the products of the PDC

55 Slide 55 / 165 The Stages of Aerobic Respiration Glycolysis The Pyruvate Dehydrogenase Complex (PDC) The Citric Acid Cycle Oxidative Phosphorylation The Electron Transport Chain (ETC) and Oxidative Phosphorylation (OP) uses the energy stored in NADH and FADH 2 to perform most of the ATP synthesis

56 Slide 56 / 165 Glycolysis This stage is identical to that used in anaerobic respiration.. 2 NAD + C 6 H 12 O 6 (Glucose) 2 ATP Gycolysis 2 NADH 4 ATP 2 C 3 H 4 O 3 (Pyruvate)

57 Slide 57 / 165 Glycolysis This stage is identical to that used in anaerobic respiration.. 2 NAD + C 6 H 12 O 6 (Glucose) 2 ATP It involves the breakdown of glucose, a 6 carbon sugar, into 2 molecules of pyruvate, a 3 carbon sugar. Gycolysis 2 NADH 4 ATP 2 C 3 H 4 O 3 (Pyruvate)

58 Slide 58 / 165 Glycolysis This stage is identical to that used in anaerobic respiration.. 2 NAD + 2 NADH C 6 H 12 O 6 (Glucose) Gycolysis 2 C 3 H 4 O 3 (Pyruvate) 2 ATP 4 ATP It involves the breakdown of glucose, a 6 carbon sugar, into 2 molecules of pyruvate, a 3 carbon sugar. Some ATP is needed to start the process, but the net result is: 2 ATPs are formed along with 2 NADHs and 2 pryuvates.

59 Slide 59 / 165 The Pyruvate Dehydrogenase Complex (PDC) The Citric Acid Cycle can only process 2-carbon molecules, and pyruvate is a 3-carbon molecule: C 3 H 4 O 3 2 NAD + 2 C 3 H 4 O 3 (Pyruvate) PDC 2 O 2 The PDC takes the 2 pyruvate molecules and converts them to 2 Acetyl Co-A molecules: these are 2 carbon molecules. 2 NADH 2 Acetyl Co-A 2 CO 2

60 Slide 60 / 165 The Pyruvate Dehydrogenase Complex (PDC) The Citric Acid Cycle can only process 2-carbon molecules, and pyruvate is a 3-carbon molecule: C 3 H 4 O 3 2 NAD + 2 C 3 H 4 O 3 (Pyruvate) PDC 2 O 2 The PDC takes the 2 pyruvate molecules and converts them to 2 Acetyl Co-A molecules: these are 2 carbon molecules. 2 NADH 2 Acetyl Co-A 2 CO 2 In doing this energy is stored by the conversion of 2 NAD + to 2 NADH and 2 O 2 molecules carry away the extra pyruvate carbons as CO 2.

61 Slide 61 / During the PDC. A B C D E Pyruvate is converted to Acetyl Co-A NAD + is converterd to NADH CO 2 is emitted All of the above None of the above

62 Slide 62 / The PDC is a process. A B C D E anaerboic fermentation aerobic All of the above None of the above

63 Slide 63 / 165 The Citric Acid Cycle The citric acid cycle is sometimes called the Krebs cycle. The cycle breaks down one Acetyl Co-A for each turn, generating 1 ATP, 3 NADH, 2 CO 2 and 1 FADH 2 per Acetyl Co-A. This supplies the NADH and FADH 2 that are required to drive the Electron Transport Process (ETP): the next stage of respiration. Since 2 Acetyl Co-A molecules were created from each glucose, the Citric Acid Cylce creates 2 ATP; 6 NADH; 4CO 2, and 2 FADH 2 for each glucose molecule.

64 Slide 64 / 165 The Citric Acid Cycle This shows one cycle, which is due to one Acetyl Co-A molecule. To account for one glucose molecule, two cycles are needed. Let's tally up the output for one cycle to confirm our results.

65 Slide 65 / 165 The Citric Acid Cycle This is one turn of the cycle, due to 1 Acetyl Co-A. Note the production of:

66 Slide 66 / 165 The Citric Acid Cycle This is one turn of the cycle, due to 1 Acetyl Co-A. Note the production of: 1 ATP

67 Slide 67 / 165 The Citric Acid Cycle This is one turn of the cycle, due to 1 Acetyl Co-A. Note the production of: 1 ATP 3 NADH

68 Slide 68 / 165 The Citric Acid Cycle This is one turn of the cycle, due to 1 Acetyl Co-A. Note the production of: 1 ATP 3 NADH 1 FADH 2

69 Slide 69 / 165 The Citric Acid Cycle This is one turn of the cycle, due to 1 Acetyl Co-A. Note the production of: 1 ATP 3 NADH 1 FADH 2 But 1 glucose molecule, yields 2 Acetyl Co-A molecules, (therefore, 2 turns of the cycle) yielding : 2 ATP 6 NADH 2 FADH 2

70 Slide 70 / 165 The Citric Acid Cycle

71 Slide 71 / The Citric Acid Cycle does not require oxygen. True False

72 Slide 72 / How many of the following would be produced with three turns of the citric acid cycle? A B C D E 1 ATP, 2 CO2, 3 NADH, and 1 FADH2 2 ATP, 2 CO2, 1 NADH, and 3 FADH2 3 ATP, 3 CO2, 3 NADH, and 3 FADH2 3 ATP, 6 CO2, 9 NADH, and 3 FADH2 38 ATP, 6 CO2, 3 NADH, and 12 FADH2

73 Slide 73 / The key molecule that is fed into the Citric Acid Cycle is. A B C D E Glucose Pyruvate Carbon Dioxide Oxygen Acetyl Co-A

74 Slide 74 / How many carbon atoms are fed into the citric acid cycle from one molecule of pyruvate?

75 Slide 75 / The products of the Citric Acid Cycle are molecules of NADH, molecules of ATP and molecules of FADH 2. A 1, 3, 1 B 2, 3, 1 C 2, 3, 3 D 3, 1, 1 E 1, 1, 1

76 Slide 76 / 165 Electron Transport Chain (ETC) and Oxidative Phosphorylation (OP) So far we've done a lot of work to just get a net gain of 4 ATPs. But we have stored a lot of potential energy in the form of NADH and FADH 2. The big energy payoff is in this stage, where we convert the energy stored in those molecules to ATP.

77 Slide 77 / 165 Electron Transport Chain (ETC) and Oxidative Phosphorylation (OP) We're now going to convert all the NADH and FADH 2 into ATP, so the energy can be stored throughout the cell. Here's what we start this cycle with. Stage NADH FADH2 ATP Glycolysis PDC CAC Total

78 Slide 78 / 165 Electron Transport Chain (ETC) and Oxidative Phosphorylation (OP) Stage NADH FADH2 ATP Glycolysis PDC CAC Total We get about 3 ATPs per NADH and 2 ATPs per FADH 2. So how many ATPs should we have at the end of this next stage?

79 Slide 79 / 165 ETC and OP Here's how that conversion to ATP takes place. The Electron Transport Chain (ETC) creates a proton gradient to be to drive Oxidative Phosphorylation. This has the same effect as charging a battery. The process of Oxidative Phosphorylation uses the potential energy of the gradient created by ETC to create a current of protons that drives the enzyme ATP Synthase, adding the third phosphate group to ADP, making ATP.

80 Slide 80 / 165 The Electron Transport Chain (ETC) The ETC generates no ATP, but enables Oxidative Phosphorylation, which accounts for most of the ATP produced. The ETC s function is to break the large free-energy drop from food into smaller steps that release energy in manageable amounts. The final electron acceptor of the electron transport chain is O 2 ; forming water (H 2 O). O 2 strongly attracts electrons in order to fill its outer shell. That attraction pulls electrons through the ETC.

81 Slide 81 / 165 The Electron Transport Chain (ETC) One way to think of the ETC is as a proton pump. This process transports electrons, through chemical reactions, out and then back through a plasma membrane. The net effect is to pump protons from the inside to the outside of a plasma membrane.

82 Slide 82 / 165 The Electron Transport Chain (ETC) This gives the inside of the membrane a negative charge, due to a shortage of protons, and the outside of the membrane a positive charge, due to an excess of protons. This can be thought of as a proton gradient. This electric potential represents stored energy, just like a battery; it can do work.

83 Slide 83 / 165 The Electron Transport Chain (ETC) Electrons are pulled through a path that weaves back and forth through the plasma membrane. They pull protons along with them; protons are attracted to electrons. On each trip out of the plasma membrane, the protons that travel with them are left outside, but the electrons move back inside. In their final reaction, they combine with O 2 to form H 2 O.

84 Slide 84 / 165 The Electron Transport Chain (ETC) This creates an electric potential that can be used to make ATP via chemiosmosis. This process can only take place near a plasma membrane. We'll see that bacteria use their cell's membrane for this purpose, while eukaryotes use the membranes of their mitochondria.

85 Slide 85 / 165 The Electron Transport Chain (ETC) The proton path in red. The electron path is shown in black. ature =re late d

86 Slide 86 / 165 Oxidative Phosphorylation Chemiosmosis The ETC creates a positive electrostatic potential outside the plasma membrane and a negative potential inside. The excess protons outside, are strongly attracted to the inside, but are blocked by the membrane. One path is open to the protons, but they must do work to use it. ATP Synthase is essentially a motor, constructed of proteins. The protons must travel through that motor in order to return to the cell, creating an electric current that powers the motor. As the motor turns, it adds a phosphate group to ADP, creating ATP. Electrical energy is transformed to chemical energy. This is an example of chemiosmosis, the use of energy in a H + gradient to drive cellular work

87 Slide 87 / 165 Oxidative Phosphorylation Chemiosmosis

88 Slide 88 / 165 Oxidative Phosphorylation Chemiosmosis

89 Slide 89 / Which metabolic pathway is common to both aerobic and anaerobic cellular respiration? A B C D E the citric acid cycle the electron transport chain glycolysis synthesis of acetyl CoA from pyruvate reduction of pyruvate to lactate

90 Slide 90 / ATP Synthase relies on the facilitated diffusion of down their gradient to produce ATP. A B C D electrons protons glucose oxygen

91 Slide 91 / The final reaction of the electrons in the ETC is to bond with to create. A B C D glucose, ATP protons, ATP hydrogen, glucose oxygen, water

92 Slide 92 / Anaerboic respiration produces ATPs while aerobic respiration produces between and ATPs. A 4, 26, 38 B 2, 48, 58 C 2, 26, 38 D 2, 36, 38 E 4, 38, 54

93 Slide 93 / 165 Aerobic Respiration We calculated earlier that we would expect to get 38 ATP molecules by the time we'd converted all the NADH and FADH 2 to ATP. The actual yield is between ATP molecules per glucose molecule. The reason for the small variance is that in some cases energy is needed to transport the NADH molecules to the site of the ETC. (But 36 to 38 ATPs per glucose is a lot better than 2, the yield from the anaerobic process.)

94 Slide 94 / 165 Oxidative Phosphorylation The Hydroelectric Analogy The Hoover Dam is a massive structure that holds back the potential energy of 9 trillion gallons of water

95 Slide 95 / 165 Oxidative Phosphorylation The Hydroelectric Analogy

96 Slide 96 / 165 Oxidative Phosphorylation The Hydroelectric Analogy Like oxidative phosphorylation, it creates a gradient then exploits the stored energy by allowing water to pass through a small pipeline, transforming it to kinetic energy.

97 Slide 97 / 165 Oxidative Phosphorylation The Hydroelectric Analogy Massive turbines are spun, causing the kinetic energy to be turned into mechanical energy which is utilized to make electrical energy.

98 Slide 98 / Which of the following is the correct sequence of events in aerobic respiration? A B C D glycolysis, PDC, ETC, citric acid cycle citric acid cycle, ETC, PDC, glycolysis glycolysis, PDC, citric acid cycle, ETC citric acid cycle, glycolysis, ETC, PDC

99 Slide 99 / Which process could be compared to how rushing water turns an electric generator? A B C D E the citric acid cycle glycolysis formation of NADH in glycolysis oxidative phosphorylation the electron transport system

100 Slide 100 / In chemiosmosis, what is the most direct source of energy that is used to convert ADP to ATP? A B C D energy released as electrons flow through the electron transport system energy released from substrate-level phosphorylation energy released from ATP synthase pumping hydrogen ions against their concentration gradient energy released from movement of protons through ATP synthase

101 Slide 101 / Energy released by the electron transport chain is used to pump H + ions into which location? A B C D outside the membrane inside the membrane into the membrane oxygen

102 Slide 102 / About how many ATP molecules are produced from the complete oxidation of 2 glucose molecules?

103 Slide 103 / The final electron acceptor of the electron transport chain that functions in oxidative phosphorylation is. A B oxygen water C NAD + D E pyruvate ADP

104 Slide 104 / 165 The Versatility of Catabolism Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration. Glycolysis accepts a wide range of carbohydrates Proteins must be digested to amino acids; amino groups can feed glycolysis or the citric acid cycle Fats are digested to glycerol which is used in glycolysis. An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate

105 Slide 105 / 165 The Versatility of Catabolism

106 Slide 106 / What is the term for metabolic pathways that release stored energy by breaking down complex molecules? A B C D E anabolic pathways catabolic pathways fermentation pathways thermodynamic pathways bioenergetic pathways

107 Slide 107 / Glycolysis is thought to be one of the most ancient of metabolic processes. Which statement supports this idea? A Glycolysis is used by all cells. B Glycolysis neither uses nor needs O 2. C D E Ancient prokaryotic cells made extensive use of glycolysis long before oxygen was present in Earth's atmosphere. None of the above All of the above

108 Slide 108 / An organism consumes large amounts of sugar, yet does not gain much weight when denied air. Its consumption of sugar increases as air is removed from its environment. When returned to normal air, the organism does fine. Which of the following best describes the organism? A B C D E It must use a molecule other than oxygen to accept electrons from the electron transport chain. It is a normal eukaryotic organism. The organismobviously lacks the citric acid cycle and electron transport chain. It is an anaerobic organism. It is a facultative organism: capable of doing anaerobic and aerobic cellular respiration.

109 Slide 109 / 165 Photosynthesis Respiration gets energy from glucose and stores it as ATP. But what is the source of glucose? And, where did the oxygen that flooded Earth 2.5 BYA come from?

110 Slide 110 / 165 Aerobic Respiration V. Photosynthesis Here's the balanced chemical equation for aerobic respiration: C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + ATP And here's the balanced chemical equation for photosynthesis: 6CO 2 + 6H 2 O + Light Energy C 6 H 12 O 6 + 6O 2

111 Slide 111 / 165 Aerobic Respiration V. Photosynthesis C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + ATP Aerobic respiration uses oxygen (O 2 ) and glucose (C 6 H 12 O 6 ) to create carbon dioxide (CO 2 ) and water (H 2 O)...and release energy. 6CO 2 + 6H 2 O + Light Energy C 6 H 12 O 6 + 6O 2 Photosynthesis is the exact opposite, it takes carbon dioxide (CO 2 ) and water (H 2 O) plus energy to make glucose (C 6 H 12 O 6 ) and oxygen (O 2 )

112 Slide 112 / 165 Photosynthesis and Respiration Summing these two equations reveals that the ATP used by cells is derived from light energy, from the sun. That is the source of energy for most life on Earth. C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + ATP (Energy) 6CO 2 + 6H 2 O + Light Energy C 6 H 12 O 6 + 6O 2

113 Slide 113 / 165 Photosynthesis and Respiration Summing these two equations reveals that the ATP used by cells is derived from light energy, from the sun. That is the source of energy for most life on Earth. C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + ATP (Energy) 6CO 2 + 6H 2 O + Light Energy C 6 H 12 O 6 + 6O 2

114 Slide 114 / 165 Photosynthesis and Respiration Summing these two equations reveals that the ATP used by cells is derived from light energy, from the sun. That is the source of energy for most life on Earth. C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + ATP (Energy) 6CO 2 + 6H 2 O + Light Energy C 6 H 12 O 6 + 6O 2

115 Slide 115 / 165 Photosynthesis and Respiration Summing these two equations reveals that the ATP used by cells is derived from light energy, from the sun. That is the source of energy for most life on Earth. C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + ATP (Energy) 6CO 2 + 6H 2 O + Light Energy C 6 H 12 O 6 + 6O 2

116 Slide 116 / 165 Photosynthesis and Respiration Summing these two equations reveals that the ATP used by cells is derived from light energy, from the sun. That is the source of energy for most life on Earth. C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + ATP (Energy) 6CO 2 + 6H 2 O + Light Energy C 6 H 12 O 6 + 6O 2

117 Slide 117 / 165 Photosynthesis and Respiration Summing these two equations reveals that the ATP used by cells is derived from light energy, from the sun. That is the source of energy for most life on Earth. C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + ATP (Energy) 6CO 2 + 6H 2 O + Light Energy C 6 H 12 O 6 + 6O 2 Light Energy ATP (Energy)

118 Slide 118 / 165 Photosynthesis and Respiration Light Energy ATP (Energy) Except for a small number of bacteria that live on chemical reactions in challenging environments, the energy for all life on Earth comes from thes processes...from the energy of sunlight. Even though not every organism undergoes photosythesis, the products that plants produce are used in reactions that consumers use. In this way, you can say that... You are solar powered!

119 Slide 119 / What are the reactants of cellular respiration? A B C D oxygen and water glucose and carbon dioxide glucose and water glucose and oxygen

120 Slide 120 / What are the products of photosynthesis? A B C D glucose and oxygen oxygen and water glucose and carbon dioxide carbon dioxide and water

121 Slide 121 / What are the reactants of photosynthesis? A B C D carbon dioxide and water oxygen and water glucose and oxygen glucose and carbon dioxide

122 Slide 122 / Photosynthesis energy, whereas cellular respiration energy. A B C D consumes, produces produces, consumes produces, produces consumes, consumes

123 Slide 123 / The source of energy for photosynthesis is. A B C D electric energy light heat kinetic energy

124 Slide 124 / 165 Our Original Questions What is the source of glucose? Where did the oxygen that flooded Earth 2.5 BYA come from?

125 Slide 125 / 165 Photosynthesis The products of photosynthesis are: oxygen (O 2 ) glucose (C 6 H 12 O 6 ) Photosynthesis produces the glucose that feeds respiration, and eventually, all of us. Photosynthesis also produces the oxygen that filled the atmosphere and made complex life, as we know it possible.

126 Slide 126 / 165 The Oxygen Catastrophe Photosynthesis and the addition of oxygen to Earth's atmosphere, began about 2.5 BYA, and was having a major impact by 2.0 BYA. This is called the Oxygen Catastrophe because it spelled the extinction of a vast number of life forms that were anaerobic and were poisoned by oxygen. Bacteria that are killed by oxygen are called obligate anaerobes. They survive today, but not when exposed to the atmosphere.

127 Slide 127 / 165 Photosynthesis 6CO 2 + 6H 2 O + Light Energy C 6 H 12 O 6 + 6O 2 This simple equation sums up the result of photosynthesis: its reactants and products. However, the processes that make photosynthesis possible are not very simple. Just like the four stages of anaerobic result in a simple equation, the process itself is complicated. Similarly, the process of photosynthesis is complicated. And in some ways similar to the steps of respiration, but backwards.

128 Slide 128 / 165 NADPH During respiration the molecules NAD + and FAD are used to store energy. Photosynthesis uses the molecule NADP +, which is a lot like NAD +, to store energy, and convey it between its two stages. The reduced form of NADP + is NADPH.

129 Slide 129 / 165 Cyclic Energy Transport There are two forms of photosynthesis. Both forms are still used, but the first form, Cyclic Energy Transport, is probably of earliest origin. And is not nearly as productive. It does not create glucose, it just converts solar energy to ATP. It is probably one of the earliest sources of energy for cells.

130 Slide 130 / 165 Cyclic Energy Transport It still operates in cells when there is too little NADP + available to create glucose. It uses only Photosystem I (which you'll learn about soon). It is very analogous to anaerobic respiration (which yields 2 ATP) versus aerobic respiration (which yields ATP). It is older and less productive but still used. That's all you need to know about this Cyclic Energy Transport.

131 Slide 131 / When the oxygen catastrophe occurred, which type of organisms died? A B C aerobic anaerobic facultative bacteria

132 Slide 132 / What are the product(s) of cyclic energy transport? A B C glucose ATP glucose and ATP

133 Slide 133 / 165 Noncyclic Energy Transport Noncyclic Energy Transport creates glucose and oxygen: it's a much more important process. And if Cyclic Energy Transport is like anaerobic respiration. Noncyclic Energy Transport is a lot like aerobic respiration.

134 Slide 134 / 165 Noncyclic Energy Transport There are two major stages to Noncyclic Energy Transport: Light Dependent Reactions Light Independent Reactions

135 Slide 135 / 165 Light Dependent Reactions Light Dependent Reactions occur in membrane bound structures called thylakoids. It's necessary to have a membrane surface separating the inside from the outside on an enclosed volume, thylakoids provide that. The inside is called the lumen; the outside is called the stroma.

136 Slide 136 / 165 Thylakoid This shows the membrane, separating the stroma from the lumen, the two photosystems and the enzymes, ATP Synthase and NADP Reductase.

137 Slide 137 / 165 Thylakoid This shows the membrane, separating the stroma from the lumen, the two photosystems and the enzymes, ATP Synthase and NADP Reductase. The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma, and a deficit in the lumen.

138 Slide 138 / 165 Thylakoid This shows the membrane, separating the stroma from the lumen, the two photosystems and the enzymes, ATP Synthase and NADP Reductase. The light reactions will use Photosystem II and Photosystem I to create an excess of protons in the stroma, and a deficit in the lumen. The only way protons can get back to the lumen, is through ATP Synthase, to produce ATP.

139 Slide 139 / 165 Chlorophyll Photosystems I and II depend on a chlorophyll, a molecule that absorbs red and violet-blue light and uses it to energize electrons to a higher energy level. Chlorophyll gives plants their green color.

140 Slide 140 / 165 Photosystems I and II First, Photosystem II (they were named in the order of discovery) absorbs light and energizes electrons. Those are used to pump protons out of the lumen, creating an electrical potential difference which is used, with ATP Synthase, to create ATP. chlorophyll Photosystem II Photosystem I

141 Slide 141 / 165 Photosystems I and II Photosystem II chlorophyll Photosystem I Then, Photosystem I absorbs more light and re-energizes those electrons. Those are used to store energy by using NADP Reductase to reduce NADP + to NADPH (adding electrons to NADP + ).

142 Slide 142 / 165 Photosystems I and II Photosystem II chlorophyll Photosystem I The ATP and NADPH are then sent to the Light Independent Reaction, the Calvin Cycle.

143 Slide 143 / 165 Light Independent Reactions This is sometimes called the Dark Reaction, but that's not accurate since it takes place in the light or the dark: it's independent of light. It takes the ATP and NADPH produced in the light cycle and uses them to convert CO 2 and H 2 O into Glucose (C 6 H 12 O 6 ) and O 2 in a multi step process.

144 Slide 144 / 165 Light Independent Reactions In each turn of the cycle the carbon of a CO 2 molecule is added to a sugar, releasing O 2. This process captures carbon and releases oxygen. This is the process that drove the Oxygen Catastrophe, flooding Earth's atmosphere with oxygen, while reducing the carbon dioxide, a greenhouse gas, in the atmosphere. This was first performed by cyanobacteria.

145 Slide 145 / 165 Light Independent Reactions The Calvin Cycle uses solar energy to create glucose.

146 Slide 146 / 165 Light Independent Reactions This shows the result of 3 turns of the cycle: 3 CO 2 are used to create 1 3-carbon sugar. Glucose requires 2 3-carbon sugars, so 6 turns of the cycle.

147 Slide 147 / 165 Light Independent Reactions In 3 turns of the cycle we use 9 ATP

148 Slide 148 / 165 Light Independent Reactions In 3 turns of the cycle we use 9 ATP and 6 NADPH

149 Slide 149 / 165 Light Independent Reactions In 3 turns of the cycle we use 9 ATP and 6 NADPH and 3 CO 2

150 Slide 150 / 165 Light Independent Reactions In 3 turns of the cycle we use 9 ATP and 6 NADPH and 3 CO 2 to make 1 3-carbon sugar

151 Slide 151 / 165 The Carbon Cycle The Calvin Cycle is also called Carbon Fixing. This means that carbon, a gas in the atmosphere, in the form of CO 2, is turned into a solid as a glucose. When glucose is used in respiration, that carbon is then released back into the atmosphere. This process of fixing and releasing carbon is called the Carbon Cycle. Carbon is not being created or destroyed, but cycles through the environment.

152 Slide 152 / The inside of the thylakoid is called the and the outside is called the. A B lumen, stroma stroma, lumen

153 Slide 153 / The Calvin Cycle takes place in the. A B C dark light dark or the light

154 Slide 154 / Oxygen is released during the. A B C D Light-dependent reaction Light-independent reaction All of the above None of the above

155 Slide 155 / The light-dependent reactions form and. A B ATP and glucose glucose and water C CO 2 and O 2 D ATP and NADPH

156 Slide 156 / Another term for forming sugar from CO2 is: A B C D carbon fixing hydrolysis respiration sweetening

157 Slide 157 / 165 Global Climate Change The carbon cycle plays a key role in Global Climate Change. Photosynthesis releases oxygen into the air, but also takes CO 2 out of the air. CO 2 is a greenhouse gas, it absorbs infrared light that would otherwise carry heat away from Earth, into space; cooling Earth.

158 Slide 158 / 165 Global Climate Change If it were not for CO 2, and other greenhouse gases, Earth would be far colder, perhaps too cold to support life as we know it. Greenhouse gases are essential for life. However, the amount of greenhouse gases in Earth's atmosphere is critical to maintaining a constant average temperature for the planet.

159 Slide 159 / 165 Global Climate Change A great deal of carbon was trapped under the surface of Earth by life forms that died over many millions of year; effectively taking that carbon out of the carbon cycle. That reduced the CO 2 in the atmosphere, reducing the temperature of Earth by allowing more heat to leave, leading to our current temperature.

160 Slide 160 / 165 Global Climate Change The hydrocarbons we use for energy (oil and natural gas) were formed from the breakdown of that long-dead plant and animal life. As we burn those fuels, we are releasing CO 2 back into the atmosphere, increasing the greenhouse gases in the atmosphere.

161 Slide 161 / 165 Global Climate Change As a result, more heat is being trapped in our atmosphere; the balance of energy brought to Earth by solar energy, and released from Earth in infrared radiation is being changed. This is causing Earth's average temperature to rise. The effect of this temperature rise is not that the temperature goes up in all places or in all years necessarily. But it is projected that there will be massive changes in climate in the future, with accompanying changes in sea level, crops, plant and animal life, etc.

162 Slide 162 / Greenhouses gases are dangerous and should be reduced as much as possible. True False

163 Slide 163 / Carbon was used from the carbon cycle, reducing CO 2 in the air, as. A B C D E the amount of life on Earth decreased as animals died and were buried under earth fermentation began All of the above None of the above

164 Slide 164 / A very warm winter in New Jersey this year would indicate that global climate change is occurring. True False

165 Slide 165 / A very cold winter in New Jersey this year would indicate that global climate change is occurring. True False