1. End Show Slide 1 of 20 Copyright Pearson Prentice Hall Biology

2. End Show Slide 2 of 20 Copyright Pearson Prentice Hall 8-1 Energy and Life

3. End Show 8-1 Energy And Life Slide 3 of 20 Copyright Pearson Prentice Hall Autotrophs and Heterotrophs Living things need energy to survive. This energy comes from food. The energy in most food comes from the sun. Where do plants get the energy they need to produce food?

4. End Show Slide 4 of 20 8-1 Energy And Life Copyright Pearson Prentice Hall Autotrophs and Heterotrophs Plants and some other types of organisms are able to use light energy from the sun to produce food.

5. End Show Slide 5 of 20 8-1 Energy And Life Copyright Pearson Prentice Hall Chemical Energy and ATP Energy comes in many forms including light, heat, and electricity. Energy can be stored in chemical compounds, too.

6. End Show 8-1 Energy And Life Slide 6 of 20 Copyright Pearson Prentice Hall Chemical Energy and ATP An important chemical compound that cells use to store and release energy is adenosine triphosphate, abbreviated ATP. ATP is used by all types of cells as their basic energy source.

7. End Show Slide 7 of 20 8-1 Energy And Life Copyright Pearson Prentice Hall Chemical Energy and ATP ATP consists of: adenine ribose (a 5-carbon sugar) 3 phosphate groups Adenine ATP Ribose 3 Phosphate groups

8. End Show Slide 8 of 20 8-1 Energy And Life Copyright Pearson Prentice Hall Chemical Energy and ATP Storing Energy ADP has two phosphate groups instead of three. A cell can store small amounts of energy by adding a phosphate group to ADP. ADP ATP Energy Partially charged battery Fully charged battery + Adenosine Diphosphate (ADP) + Phosphate Adenosine Triphosphate (ATP)

9. End Show Slide 9 of 20 8-1 Energy And Life Copyright Pearson Prentice Hall Chemical Energy and ATP Releasing Energy Energy stored in ATP is released by breaking the chemical bond between the second and third phosphates. P ADP 2 Phosphate groups

10. End Show 8-1 Energy And Life Slide 10 of 20 Copyright Pearson Prentice Hall Chemical Energy and ATP What is the role of ATP in cellular activities?

11. End Show Slide 11 of 20 8-1 Energy And Life Copyright Pearson Prentice Hall Chemical Energy and ATP The energy from ATP is needed for many cellular activities, including active transport across cell membranes, protein synthesis and muscle contraction. ATP’s characteristics make it exceptionally useful as the basic energy source of all cells.

12. End Show Slide 12 of 20 8-1 Energy And Life Copyright Pearson Prentice Hall Using Biochemical Energy Most cells have only a small amount of ATP, because it is not a good way to store large amounts of energy. Cells can regenerate ATP from ADP as needed by using the energy in foods like glucose.

13. End Show - or - Continue to: Click to Launch: Slide 13 of 20 Copyright Pearson Prentice Hall 8-1

14. End Show Slide 14 of 20 Copyright Pearson Prentice Hall 8-1 Organisms that make their own food are called a.autotrophs. b.heterotrophs. c.decomposers. d.consumers.

15. End Show Slide 15 of 20 Copyright Pearson Prentice Hall 8-1 Most autotrophs obtain their energy from a.chemicals in the environment. b.sunlight. c.carbon dioxide in the air. d.other producers.

16. End Show Slide 16 of 20 Copyright Pearson Prentice Hall 8-1 How is energy released from ATP? a.A phosphate is added. b.An adenine is added. c.A phosphate is removed. d.A ribose is removed.

17. End Show Slide 17 of 20 Copyright Pearson Prentice Hall 8-1 How is it possible for most cells to function with only a small amount of ATP? a.Cells do not require ATP for energy. b.ATP can be quickly regenerated from ADP and P. c.Cells use very small amounts of energy. d.ATP stores large amounts of energy.

18. End Show Slide 18 of 20 Copyright Pearson Prentice Hall 8-1 Compared to the energy stored in a molecule of glucose, ATP stores a.much more energy. b.much less energy. c.about the same amount of energy. d.more energy sometimes and less at others.

19. END OF SECTION

20. End Show Slide 20 of 28 Copyright Pearson Prentice Hall Biology

21. End Show Slide 21 of 28 Copyright Pearson Prentice Hall 8-2 Photosynthesis: An Overview

22. End Show Slide 22 of 28 8-2 Photosynthesis: An Overview Copyright Pearson Prentice Hall 8-2 Photosynthesis: An Overview The key cellular process identified with energy production is photosynthesis. Photosynthesis is the process in which green plants use the energy of sunlight to convert water and carbon dioxide into high-energy carbohydrates and oxygen.

23. End Show Slide 23 of 28 8-2 Photosynthesis: An Overview Copyright Pearson Prentice Hall Investigating Photosynthesis What did the experiments of van Helmont, Priestley, and Ingenhousz reveal about how plants grow?

24. End Show Slide 24 of 28 8-2 Photosynthesis: An Overview Copyright Pearson Prentice Hall Investigating Photosynthesis Research into photosynthesis began centuries ago.

25. End Show Slide 25 of 28 8-2 Photosynthesis: An Overview Copyright Pearson Prentice Hall Investigating Photosynthesis Van Helmont’s Experiment In the 1600s, Jan van Helmont wanted to find out if plants grew by taking material out of the soil. He determined the mass of a pot of dry soil and a small seedling, planted the seedling in the pot, and watered it regularly. After five years, the seedling was a small tree and had gained 75 kg, but the soil’s mass was almost unchanged.

26. End Show Slide 26 of 28 8-2 Photosynthesis: An Overview Copyright Pearson Prentice Hall Investigating Photosynthesis Van Helmont concluded that the gain in mass came from water because water was the only thing he had added. His experiment accounts for the “hydrate,” or water, portion of the carbohydrate produced by photosynthesis. But where does the carbon of the “carbo-” portion come from?

27. End Show Slide 27 of 28 8-2 Photosynthesis: An Overview Copyright Pearson Prentice Hall Investigating Photosynthesis Although van Helmont did not realize it, carbon dioxide in the air made a major contribution to the mass of his tree. In photosynthesis, the carbon in carbon dioxide is used to make sugars and other carbohydrates. Van Helmont had only part of the story, but he had made a major contribution to science.

28. End Show Slide 28 of 28 8-2 Photosynthesis: An Overview Copyright Pearson Prentice Hall Investigating Photosynthesis Priestley’s Experiment More than 100 years after van Helmont’s experiment, Joseph Priestley provided another insight into the process of photosynthesis. Priestley took a candle, placed a glass jar over it, and watched as the flame gradually died out. He reasoned that the flame needed something in the air to keep burning and when it was used up, the flame went out. That substance was oxygen.

29. End Show Slide 29 of 28 8-2 Photosynthesis: An Overview Copyright Pearson Prentice Hall Investigating Photosynthesis Priestley then placed a live sprig of mint under the jar and allowed a few days to pass. He found that the candle could be relighted and would remain lighted for a while. The mint plant had produced the substance required for burning. In other words, it had released oxygen.

30. End Show Slide 30 of 28 8-2 Photosynthesis: An Overview Copyright Pearson Prentice Hall Investigating Photosynthesis Jan Ingenhousz Later, Jan Ingenhousz showed that the effect observed by Priestley occurred only when the plant was exposed to light. The results of both Priestley’s and Ingenhousz’s experiments showed that light is necessary for plants to produce oxygen.

31. End Show Slide 31 of 28 8-2 Photosynthesis: An Overview Copyright Pearson Prentice Hall Investigating Photosynthesis The experiments performed by van Helmont, Priestley, and Ingenhousz led to work by other scientists who finally discovered that, in the presence of light, plants transform carbon dioxide and water into carbohydrates, and they also release oxygen.

32. End Show Slide 32 of 28 8-2 Photosynthesis: An Overview Copyright Pearson Prentice Hall The Photosynthesis Equation What is the overall equation for photosynthesis?

33. End Show Slide 33 of 28 8-2 Photosynthesis: An Overview Copyright Pearson Prentice Hall The Photosynthesis Equation The equation for photosynthesis is: 6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O 2 carbon dioxide + water sugars + oxygen Light

34. End Show Slide 34 of 28 8-2 Photosynthesis: An Overview Copyright Pearson Prentice Hall The Photosynthesis Equation Photosynthesis uses the energy of sunlight to convert water and carbon dioxide into high-energy sugars and oxygen.

35. End Show Slide 35 of 28 8-2 Photosynthesis: An Overview Copyright Pearson Prentice Hall The Photosynthesis Equation O2O2 CO 2 + H 2 0 Sugar ADP NADP + Light-Dependent Reactions (thylakoids) H2OH2O ATP NADPH Calvin Cycle (stroma) Light energy

36. End Show Slide 36 of 28 8-2 Photosynthesis: An Overview Copyright Pearson Prentice Hall Light and Pigments What is the role of light and chlorophyll in photosynthesis?

37. End Show Slide 37 of 28 8-2 Photosynthesis: An Overview Copyright Pearson Prentice Hall Light and Pigments How do plants capture the energy of sunlight? In addition to water and carbon dioxide, photosynthesis requires light and chlorophyll.

38. End Show Slide 38 of 28 8-2 Photosynthesis: An Overview Copyright Pearson Prentice Hall Light and Pigments Plants gather the sun's energy with light-absorbing molecules called pigments. The main pigment in plants is chlorophyll. There are two main types of chlorophyll: chlorophyll a chlorophyll b

39. End Show Slide 39 of 28 8-2 Photosynthesis: An Overview Chlorophyll absorbs light well in the blue-violet and red regions of the visible spectrum. Copyright Pearson Prentice Hall Light and Pigments Wavelength (nm) Estimated Absorption (%) 100 80 60 40 20 0 400 450 500 550 600 650 700 750 Chlorophyll b Chlorophyll a Wavelength (nm)

40. End Show Slide 40 of 28 8-2 Photosynthesis: An Overview Copyright Pearson Prentice Hall Light and Pigments Chlorophyll does not absorb light will in the green region of the spectrum. Green light is reflected by leaves, which is why plants look green. Estimated Absorption (%) 100 80 60 40 20 0 400 450 500 550 600 650 700 750 Chlorophyll b Chlorophyll a Wavelength (nm)

41. End Show Slide 41 of 28 8-2 Photosynthesis: An Overview Copyright Pearson Prentice Hall Light and Pigments Light is a form of energy, so any compound that absorbs light also absorbs energy from that light. When chlorophyll absorbs light, much of the energy is transferred directly to electrons in the chlorophyll molecule, raising the energy levels of these electrons. These high-energy electrons are what make photosynthesis work.

42. End Show - or - Continue to: Click to Launch: Slide 42 of 28 Copyright Pearson Prentice Hall 8-2

43. End Show Slide 43 of 28 Copyright Pearson Prentice Hall 8-2 In van Helmont's experiment, most of the added mass of the tree came from a.soil and carbon dioxide. b.water and carbon dioxide. c.oxygen and carbon dioxide. d.soil and oxygen.

44. End Show Slide 44 of 28 Copyright Pearson Prentice Hall 8-2 Plants use the sugars produced in photosynthesis to make a.oxygen. b.starches. c.carbon dioxide. d.protein.

45. End Show Slide 45 of 28 Copyright Pearson Prentice Hall 8-2 The raw materials required for plants to carry out photosynthesis are a.carbon dioxide and oxygen. b.oxygen and sugars. c.carbon dioxide and water. d.oxygen and water.

46. End Show Slide 46 of 28 Copyright Pearson Prentice Hall 8-2 The principal pigment in plants is a.chloroplast. b.chlorophyll. c.carotene. d.carbohydrate.

47. End Show Slide 47 of 28 Copyright Pearson Prentice Hall 8-2 The colors of light that are absorbed by chlorophylls are a.green and yellow. b.green, blue, and violet. c.blue, violet, and red. d.red and yellow.

48. END OF SECTION

49. End Show Slide 49 of 51 Copyright Pearson Prentice Hall Biology

50. End Show Slide 50 of 51 Copyright Pearson Prentice Hall 8-3 The Reactions of Photosynthesis

51. End Show Slide 51 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Inside a Chloroplast In plants, photosynthesis takes place inside chloroplasts. Plant Plant cells Chloroplast

52. End Show Slide 52 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Inside a Chloroplast Chloroplasts contain thylakoids—saclike photosynthetic membranes. Chloroplast Single thylakoid

53. End Show Slide 53 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Inside a Chloroplast Thylakoids are arranged in stacks known as grana. A singular stack is called a granum. Granum Chloroplast

54. End Show Slide 54 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Inside a Chloroplast Proteins in the thylakoid membrane organize chlorophyll and other pigments into clusters called photosystems, which are the light-collecting units of the chloroplast. Chloroplast Photosystems

55. End Show Slide 55 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Inside a Chloroplast Chloroplast Light H2OH2O O2O2 CO 2 Sugars NADP + ADP + P Calvin Cycle Light- dependent reactions Calvin cycle

56. End Show Slide 56 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Electron Carriers When electrons in chlorophyll absorb sunlight, the electrons gain a great deal of energy. Cells use electron carriers to transport these high- energy electrons from chlorophyll to other molecules.

57. End Show Slide 57 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Electron Carriers One carrier molecule is NADP +. Electron carriers, such as NADP +, transport electrons. NADP + accepts and holds 2 high-energy electrons along with a hydrogen ion (H + ). This converts the NADP + into NADPH.

58. End Show Slide 58 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Light-Dependent Reactions The light-dependent reactions require light. The light-dependent reactions produce oxygen gas and convert ADP and NADP + into the energy carriers ATP and NADPH.

59. End Show Slide 59 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Light-Dependent Reactions

60. End Show Slide 60 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Photosystem II Light-Dependent Reactions Photosynthesis begins when pigments in photosystem II absorb light, increasing their energy level.

61. End Show Slide 61 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Light-Dependent Reactions Photosystem II These high-energy electrons are passed on to the electron transport chain. Electron carriers High-energy electron

62. End Show Slide 62 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Light-Dependent Reactions Photosystem II 2H 2 O Enzymes on the thylakoid membrane break water molecules into: Electron carriers High-energy electron

63. End Show Slide 63 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Light-Dependent Reactions Photosystem II 2H 2 O hydrogen ions oxygen atoms energized electrons + O 2 Electron carriers High-energy electron

64. End Show Slide 64 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Light-Dependent Reactions Photosystem II 2H 2 O + O 2 The energized electrons from water replace the high-energy electrons that chlorophyll lost to the electron transport chain. High-energy electron

65. End Show Slide 65 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Light-Dependent Reactions Photosystem II 2H 2 O As plants remove electrons from water, oxygen is left behind and is released into the air. + O 2 High-energy electron

66. End Show Slide 66 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Light-Dependent Reactions Photosystem II 2H 2 O The hydrogen ions left behind when water is broken apart are released inside the thylakoid membrane. + O 2 High-energy electron

67. End Show Slide 67 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Light-Dependent Reactions Photosystem II 2H 2 O Energy from the electrons is used to transport H + ions from the stroma into the inner thylakoid space. + O 2

68. End Show Slide 68 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Light-Dependent Reactions Photosystem II 2H 2 O High-energy electrons move through the electron transport chain from photosystem II to photosystem I. + O 2 Photosystem I

69. End Show Slide 69 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Light-Dependent Reactions 2H 2 O Pigments in photosystem I use energy from light to re-energize the electrons. + O 2 Photosystem I

70. End Show Slide 70 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Light-Dependent Reactions 2H 2 O NADP + then picks up these high-energy electrons, along with H + ions, and becomes NADPH. + O 2 2 NADP + 2 NADPH 2

71. End Show Slide 71 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Light-Dependent Reactions 2H 2 O As electrons are passed from chlorophyll to NADP +, more H + ions are pumped across the membrane. + O 2 2 NADP + 2 NADPH 2

72. End Show Slide 72 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Light-Dependent Reactions 2H 2 O Soon, the inside of the membrane fills up with positively charged hydrogen ions, which makes the outside of the membrane negatively charged. + O 2 2 NADP + 2 NADPH 2

73. End Show Slide 73 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Light-Dependent Reactions 2H 2 O The difference in charges across the membrane provides the energy to make ATP + O 2 2 NADP + 2 NADPH 2

74. End Show Slide 74 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Light-Dependent Reactions 2H 2 O H + ions cannot cross the membrane directly. + O 2 ATP synthase 2 NADP + 2 NADPH 2

75. End Show Slide 75 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Light-Dependent Reactions 2H 2 O The cell membrane contains a protein called ATP synthase that allows H + ions to pass through it + O 2 ATP synthase 2 NADP + 2 NADPH 2

76. End Show Slide 76 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Light-Dependent Reactions 2H 2 O As H + ions pass through ATP synthase, the protein rotates. + O 2 ATP synthase 2 NADP + 2 NADPH 2

77. End Show Slide 77 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Light-Dependent Reactions 2H 2 O As it rotates, ATP synthase binds ADP and a phosphate group together to produce ATP. + O 2 2 NADP + 2 NADPH 2 ATP synthase ADP

78. End Show Slide 78 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall Light-Dependent Reactions 2H 2 O Because of this system, light-dependent electron transport produces not only high-energy electrons but ATP as well. + O 2 ATP synthase ADP 2 NADP + 2 NADPH 2

79. End Show Slide 79 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall The Calvin Cycle What is the Calvin cycle?

80. End Show Slide 80 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall The Calvin Cycle The Calvin cycle uses ATP and NADPH from the light-dependent reactions to produce high-energy sugars. Because the Calvin cycle does not require light, these reactions are also called the light-independent reactions.

81. End Show Slide 81 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall The Calvin Cycle Six carbon dioxide molecules enter the cycle from the atmosphere and combine with six 5-carbon molecules. CO 2 Enters the Cycle

82. End Show Slide 82 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall The Calvin Cycle The result is twelve 3-carbon molecules, which are then converted into higher-energy forms.

83. End Show Slide 83 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall The Calvin Cycle The energy for this conversion comes from ATP and high-energy electrons from NADPH. 12 NADPH 12 12 ADP 12 NADP + Energy Input

84. End Show Slide 84 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall The Calvin Cycle Two of twelve 3-carbon molecules are removed from the cycle. Energy Input 12 NADPH 12 12 ADP 12 NADP +

85. End Show Slide 85 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall The Calvin Cycle The molecules are used to produce sugars, lipids, amino acids and other compounds. 12 NADPH 12 12 ADP 12 NADP + 6-Carbon sugar produced Sugars and other compounds

86. End Show Slide 86 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall The Calvin Cycle The 10 remaining 3-carbon molecules are converted back into six 5-carbon molecules, which are used to begin the next cycle. 12 NADPH 12 12 ADP 12 NADP + 5-Carbon Molecules Regenerated Sugars and other compounds 6 6 ADP

87. End Show Slide 87 of 51 8-3 The Reactions of Photosynthesis Copyright Pearson Prentice Hall The Calvin Cycle The two sets of photosynthetic reactions work together. The light-dependent reactions trap sunlight energy in chemical form. The light-independent reactions use that chemical energy to produce stable, high- energy sugars from carbon dioxide and water.

88. End Show - or - Continue to: Click to Launch: Slide 88 of 51 Copyright Pearson Prentice Hall 8-3

89. End Show Slide 89 of 51 Copyright Pearson Prentice Hall 8-3 In plants, photosynthesis takes place inside the a.thylakoids. b.chloroplasts. c.photosystems. d.chlorophyll.

90. End Show Slide 90 of 51 Copyright Pearson Prentice Hall 8-3 Energy to make ATP in the chloroplast comes most directly from a.hydrogen ions flowing through an enzyme in the thylakoid membrane. b.transfer of a phosphate from ADP. c.electrons moving through the electron transport chain. d.electrons transferred directly from NADPH.

91. End Show Slide 91 of 51 Copyright Pearson Prentice Hall 8-3 NADPH is produced in light-dependent reactions and carries energy in the form of a.ATP. b.high-energy electrons. c.low-energy electrons. d.ADP.

92. End Show Slide 92 of 51 Copyright Pearson Prentice Hall 8-3 What is another name for the Calvin cycle? a.light-dependent reactions b.light-independent reactions c.electron transport chain d.photosynthesis

93. End Show Slide 93 of 51 Copyright Pearson Prentice Hall 8-3 Which of the following factors does NOT directly affect photosynthesis? a.wind b.water supply c.temperature d.light intensity

94. END OF SECTION