1. Mader: Biology 8 th Ed. Photosynthesis

2. Mader: Biology 8 th Ed. PHOTOSYNTHESIS 1. WHAT ARE SOME PROPERTIES OF SUNLIGHT THAT ARE RELATED TO PHOTOSYNTHESIS? 2. HOW IS THE STRUCTURE OF THE CHLOROPLAST RELATED TO ITS ROLE IN PHOTOSYNTHESIS? 3. WHAT IS THE PROCESS OF PHOTOSYNTHESIS AND ITS VARIATIONS?

3. Mader: Biology 8 th Ed. PROPERITES OF LIGHT VISIBLE LIGHT IS A PORTION OF THE ELECTROMAGNECTIC SPECTRUM THAT CAN BE BROKEN INTO THE COLORS OF THE RAINBOW. R O Y G B I V LONG WAVESSHORT WAVES LESS ENERGYMORE ENERGY

4. Mader: Biology 8 th Ed. LIGHT TRAVELS IN A WAVE LIKE PATTERN, BUT IS ACTUALLY DISCRETE PACKETS OF ENERGY CALLED PHOTONS.

5. Mader: Biology 8 th Ed. LIGHT AND PLANTS PLANTS ABSORB THE BLUE-VIOLET AND ORANGE-RED PARTS OF THE SPECTRUM PLANTS REFLECT MOST OF THE GREEN WAVES HENCE THEY APPREAR GREEN

6. Mader: Biology 8 th Ed. Photosynthetic Pigments Most pigments absorb only some wavelengths of light and reflect or transmit the other wavelengths. – Absorption Spectra  Organic molecules and processes within organisms are chemically adapted to visible light.

7. Mader: Biology 8 th Ed. Photosynthetic Pigments and Photosynthesis

8. Mader: Biology 8 th Ed. STRUCTURE OF THE CHLOROPLAST THE CHLOROPLAST IS AN AMAZING SOLAR COLLECTOR!!

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13. Photosynthetic Organisms Photosynthesis transforms solar energy into the chemical energy of a carbohydrate. – All organisms use organic molecules produced by photosynthesizers as a source of chemical energy.

14. Mader: Biology 8 th Ed. Flowering Plants The green portions of plants, particularly leaves, carry on photosynthesis. – Leaf of flowering plant contains mesophyll tissue.  Contains cells specialized to carry on photosynthesis.

15. Mader: Biology 8 th Ed. Flowering Plants CO 2 enters leaf through stomata. CO 2 and water diffuse into chloroplasts. – Double membrane surrounds fluid (stroma).  Inner membrane system within stroma form flattened sacs (thylakoids).  Often stacked to form grana. – Chlorophyll and other pigments within thylakoid membranes are capable of absorbing solar energy.

16. Mader: Biology 8 th Ed. THE PROCESS OF PHOTOSYNTHESIS

17. Mader: Biology 8 th Ed. Photosynthesis Carbon dioxide + water + solar energy yields glucose and oxygen. 6 CO 2 + 6 H 2 O + energy  C 6 H 12 O 6 + 6 O 2 Chloroplasts capture solar energy and convert it via electron transport system and chemiosmosis to ATP.

18. Mader: Biology 8 th Ed. LIGHT DEPENDENT RX IN CHLOROPLAST PHOTOSYSTEM I PHOTOSYSTEM II LIGHT INDEPENDENT RX(CALVIN CYCLE) IN CHLOROPLAST H2OH2OCO 2 SUN OXYGEN GLUCOSE PHOTOSYNTHESIS S NADPH ATP ADP NADP

19. Mader: Biology 8 th Ed. Photosynthetic Reaction Light Reaction - Chlorophyll absorbs solar energy and energizes electrons. – Electrons move down electron transport chain.  Solar energy  ATP, NADPH Calvin Cycle Reaction - CO 2 is taken up and reduced to a carbohydrate. – Reduction requires ATP and NADPH.  ATP, NADPH  Carbohydrate

20. Mader: Biology 8 th Ed. Photosynthesis Overview

21. Mader: Biology 8 th Ed. Light Reactions Light reactions consist of two electron pathways: – Noncyclic electron pathway – Cyclic electron pathway Both pathways produce ATP, but only the noncyclic pathway also produces NADPH.

22. Mader: Biology 8 th Ed. Cyclic Electron Pathway Cyclic pathway begins when PS I pigment complex absorbs solar energy and is passed from one pigment to another until it is concentrated in a reaction center. – Pathway only results in ATP production.

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24. Noncyclic Electron Pathway Electron flow can be traced from water to a molecule of NADPH. Uses two photosystems, PS I and PS II. – Photosystem consists of pigment complex and electron acceptor molecules in the thylakoid membrane.  Pigment complex helps gather solar energy.

25. Mader: Biology 8 th Ed. 08_05 The light-dependent reactions: the noncyclic electron pathway Slide number: 2 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

26. Mader: Biology 8 th Ed. 08_05 The light-dependent reactions: the noncyclic electron pathway Slide number: 3 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. electron acceptor Energy level sun e–e– e–e– reaction-center chlorophyll a Photosystem II

27. Mader: Biology 8 th Ed. 08_05 The light-dependent reactions: the noncyclic electron pathway Slide number: 4 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. electron acceptor Energy level sun e–e– e–e– reaction-center chlorophyll a Photosystem II ATP ADP + P Electron transport system CH 2 OCO 2 Light-independent reactions: (Calvin cycle)

28. Mader: Biology 8 th Ed. 08_05 The light-dependent reactions: the noncyclic electron pathway Slide number: 5 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. sun electron acceptor reaction-center chlorophyll a Photosystem I electron acceptor Energy level sun e–e– e–e– reaction-center chlorophyll a Photosystem II ATP ADP + P Electron transport system CH 2 OCO 2 Light-independent reactions: (Calvin cycle)

29. Mader: Biology 8 th Ed. 08_05 The light-dependent reactions: the noncyclic electron pathway Slide number: 6 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. sun electron acceptor reaction-center chlorophyll a Photosystem I electron acceptor Energy level sun e–e– e–e– reaction-center chlorophyll a Photosystem II ATP ADP + P Electron transport system CH 2 OCO 2 Light-independent reactions: (Calvin cycle) e–e– H+H+ NADP + NADPH

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31. Thylakoid Organization

32. Mader: Biology 8 th Ed. SUMMARY CYCLIC PATHWAY-An excited electron from PS I is used to convert ADP to ATP via ETS & Chemiosmosis and the low energy electron returns to PS I

33. Mader: Biology 8 th Ed. SUMMARY NONCYCLIC PATHWAY- 1. Excited electron in PS II converts ADP to ATP via ETS & Chemiosmosis 2. Low energy electron from PS II goes to PS I where it is excited and changes NADP to NADPH 3. Water is split to release Oxygen, provide Hydrogen ions in the thylakoid space and electrons to replace lost electrons of PS II

34. Mader: Biology 8 th Ed. LIGHT INDEPENDENT REACTIONS

35. Mader: Biology 8 th Ed. Calvin Cycle Reactions Calvin cycle is a series of reactions that produce carbohydrates before returning to the starting point again. – Utilizes atmospheric carbon dioxide to produce carbohydrates. Includes:  Carbon dioxide fixation  Carbon dioxide reduction  RuBP Regeneration

36. Mader: Biology 8 th Ed. 08_08 The light-independent reactions: the Calvin cycle Slide number: 2 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

37. Mader: Biology 8 th Ed. 08_08 The light-independent reactions: the Calvin cycle Slide number: 3 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 3 CO 2 intermediate 3 C 6 3 RuBP C 5 Calvin cycle CO 2 fixation

38. Mader: Biology 8 th Ed. 08_08 The light-independent reactions: the Calvin cycle Slide number: 4 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 3 CO 2 intermediate 3 C 6 6 PGA C 3 3 RuBP C 5 Calvin cycle CO 2 fixation 6 ATP P 6 ADP + 6 6 PGAP C 3 CO 2 reduction

39. Mader: Biology 8 th Ed. 08_08 The light-independent reactions: the Calvin cycle Slide number: 5 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 3 CO 2 intermediate 3 C 6 6 PGA C 3 3 RuBP C 5 Calvin cycle CO 2 fixation 6 ATP P 6 ADP + 6 6 PGAP C 3 CO 2 reduction 6 PGAL C 3 6 NADP + 6 NADPH

40. Mader: Biology 8 th Ed. 08_08 The light-independent reactions: the Calvin cycle Slide number: 6 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 3 CO 2 intermediate 3 C 6 6 PGA C 3 3 RuBP C 5 Calvin cycle CO 2 fixation 6 ATP P 6 ADP + 6 6 PGAP C 3 CO 2 reduction Net gain of one PGAL x 2 GlucoseOther organic molecules 6 PGAL C 3 6 NADP + 6 NADPH

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42. Calvin Cycle Reactions Carbon Dioxide Fixation – CO 2 is attached to RuBP. The result is a 6- carbon molecule which splits into two 3- carbon molecules.  Rubisco speeds up this reaction.

43. Mader: Biology 8 th Ed. Calvin Cycle Reactions Reduction of Carbon Dioxide

44. Mader: Biology 8 th Ed. Calvin Cycle Reactions Regeneration of RuBP

45. Mader: Biology 8 th Ed. Importance of Calvin Cycle PGAL (glyceraldehyde-3-phosphate) is the product of the Calvin cycle that can be converted to a variety of organic molecules. – A plant can utilize the hydrocarbon skeleton of PGAL to form fatty acids and glycerol, which are combined in plant oils.

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47. C 3 PHOTOSYNTHESIS WHEN CO 2 COMBINES WITH RuBP DIRECTLY. MOST PLANTS ARE C 3 PLANTS. RICE, WHEAT, AND OATS. THESE ARE MODERATELY PRODUCTIVE PLANTS

48. Mader: Biology 8 th Ed. VARIATIONS OF C 3 PHOTOSYNTHESIS

49. Mader: Biology 8 th Ed. C 4 Photosynthesis In C 4 leaf, bundle sheath cells and mesophyll cells contain chloroplasts. Mesophyll cells are arranged concentrically around the bundle sheath cells. In hot, dry climates, net photosynthetic rate of C 4 plants is about 2-3 times that of C 3 plants. – Avoid photorespiration

50. Mader: Biology 8 th Ed. C 3 vs C 4

51. Mader: Biology 8 th Ed. Carbon Dioxide Fixation in C 3 and C 4 Plants

52. Mader: Biology 8 th Ed. C 4 PLANTS CO 2 FORMS AN INTERMEDIATE THAT IS A C 4 COMPOUND WHICH SPLITS AND THEN ENTERS THE CALVIN CYCLE WHEN CONDITIONS ARE MORE FAVORABLE. SUGAR CANE, CORN, BERMUDA GRASS – HIGH PRODUCERS

53. Mader: Biology 8 th Ed. CAM Photosynthesis Crassulacean-Acid Metabolism – C 4 plants partition carbon fixation in space, while CAM partitions by time.  During the night, CAM plants fix CO 2, forming C 4 molecules, which are stored in large vacuoles.  C 4 molecules release CO 2 to Calvin cycle when NADPH and ATP are available.  Water Conservation

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55. CAM PLANTS CO 2 FORMS AN INTERMEDIATE THAT IS A C 4 COMPOUND, WHICH SPLITS AND THEN ENTERS THE CALVIN CYCLE ONLY AT NIGHT. DESERT PLANTS

56. Mader: Biology 8 th Ed. Review 1. WRITE THE BALANCED EQUATION FOR PHOTOSYNTHESIS AND IDENTIFY REACTANTS AND PRODUCTS 2. WHY ARE PLANTS GREEN? 3. DRAW AND LABEL THE CHLOROPLAST

57. Mader: Biology 8 th Ed. 1. Photosynthesis Carbon dioxide + water + solar energy yields glucose and oxygen. 6 CO 2 + 6 H 2 O + energy  C 6 H 12 O 6 + 6 O 2 REACTANTSPRODUCTS

58. Mader: Biology 8 th Ed. 2. PLANTS ABSORB THE BLUE-VIOLET AND ORANGE-RED PARTS OF THE SPECTRUM PLANTS REFLECT MOST OF THE GREEN WAVES HENCE THEY APPREAR GREEN

59. Mader: Biology 8 th Ed. 2. Photosynthetic Pigments and Photosynthesis

60. Mader: Biology 8 th Ed. 3. CHLOROPLAST

61. Mader: Biology 8 th Ed. LABEL THE DIAGRAM BELOW

62. Mader: Biology 8 th Ed. a.H2O c. CO 2 : b. Oxygen d. glucose : e. ADP g. NADP h. ATP f. NADPH

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