Energy Capturing Pathways

1. Energy Capturing Pathways I. Introduction A. History

2. 1.VanHelmont, 1630, proved plants need water 2.Priestly, 1772, proved plants need gas (phlogiston) 3.Ingenhaus, 1779, proved plants need sunlight 4.DeSaussure, 1804, organized all the pieces 5.Van Neil, 1930, showed hydrogen in the glucose comes from splitting water

3. B. Reduction/Oxidation Reactions

4. 1.Redox= giving and receivingof electronsor energy Figure 9.3

5. C. NADP+and Energy Transfer

6. Figure 9.4

7. II. Photosynthesis A. Organisms

8. 1.Autotrophs are organisms that can fix energy into carbon molecules. Figure 10.2

9. B. Structures

10. 1.Chloroplasts Figure 10.3

11. C. Background Info.

12. 1.Light Properties Figure 10.6

13. 1.Light Properties Figure 10.7

14. 2.Pigments a. Chlorophylls are primary and reflect greens. Figure 10.10

15. 2.Pigments b. Xanthophylls are secondary and reflect yellows.

16. 2.Pigments and reflect orangesand protect chlorophylls. c.Carotenoids are secondary

17. 2.Pigments Figure 10.9

18. III. Light Dependent Reactions A. Electron Excitation

19. 1. Magnesium absorbs light energy and electrons get excited Figure 10.11

20. B. Where

21. 1. Chloroplasts light dependent reactions via chlorophyll pigments in the thylakoid membraneof chloroplasts Figure 10.12

22. C. Steps

23. 1. Non-cyclic electron flow Figure 10.13

24. Non-cyclic Steps a. Light excites electrons of magnesium (oxidizes) of chlorophyll of photo-system II and I. b. Electrons from II are passed through an ETC to make ATP, while electrons from I are passed through an ETC to reduce NADP+. c. Electrons from II are used to backfill I chlorophyll that lost electrons to NADP+. d. Water is split by II to fill electrons lost to I by stealing electrons from hydrogen and provide a hydrogen to form NADPH +H+.

25. 2. Cyclic electron flow Figure 10.15

26. Cyclic Steps a. Light excites electrons of magnesium (oxidizes) of chlorophyll of photo-system I only. b. Electrons from I are passed through an ETC to make ATP only. c. Electrons from I are used to backfill I magnesium of the original chlorophyll. d. Water is not split.

27. Figure 10.17

28. D. Outcomes

29. The ATPandNADPH+H+ chloroplast stroma used to energize CO2(ATP) &add hydrogen(NADPH +H+) TheO2to the stomata to be expelled or to mitochondria Do plants need to keep expelling O2 for their benefit? Or yours?

30. IV. Light Independent Rxns. A. Where

31. 1. Chloroplasts The eight step process (Calvin cycle, the light independent reactions, or the DARK reactions) in chloroplast’s stroma. Figure 10.3

32. B. Steps

33. Figure 10.18

34. a. Rubisco attaches 3CO2 to RuBP b. Requires 6ATP and 6NADPH+ H+to make 6G3P c. Separate 1G3P and hold in reserve d. Rearrange other 5G3P back into RuBP requiring 3ATP e. Repeat as long as you have enough ???? 1Glucose requires 18ATP + 12NADPH + H+

35. C. Outcomes What to do with the glucose?

36. V. Alternative Strategies A. Photorespiration 1. Definition 2. Mechanism

37. B. C3 Plants 1. Definition 2. Mechanism

38. C3 plants go senescent rice, wheat, some grasses, and soybean

39. C. C4 Plants 1. Definition 2. Mechanism

40. C4 plants turn CO2into acid molecules then break up to giveCO2to Rubisco sugarcane, corn, and other grasses Figure 10.19

41. D. CAM Plants 1. Definition 2. Mechanism

42. CAM plants completely separate light from dark reactions cactus, pineapples, and succulents

43. C4versus CAM plants Figure 10.20

44. Figure 10.21

45. Learningis the key togrowing.