1. Energy Capturing Pathways (Photosynthesis) I. Introduction A. History

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

3. Photosynthesis Overview Figure 6.3

4. Autotrophs (self feeders) are organisms that can fix energy into carbon molecules. Figure 6.1 Page 88

5. B. Background Information 1. Chloroplast Structure

6. Photosynthetic Structures Figure 6.2Figure 6.2

7. 2. Light Properties & Pigments

8. Light Properties Figure 6.4

9. Pigments Chlorophylls are primaryand reflect greens. Xanthophylls are secondaryand reflect reds. and reflect oranges and protect chlorophylls. Carotenoids are secondary Magnesium Figure 6.5

10. C. Light Dependent Reactions 1. Where

11. The light dependent reactions occur via chlorophyll pigments in the thylakoid membrane of chloroplasts. Why is this solution red?

12. 2. Steps

13. Light Dependent Reaction Steps Figure 6.6

14. Making ATP & NADPH + H + with sunlight Figure 6.7

15. Light Dependent Reaction Steps 1. Light excites electrons of magnesium of the chlorophyll molecules of photo-system II and I.I. 2. Electrons from II are passed through an ETC to make ATP, while electrons from I are passed through an ETC to make NADPH + H+.H+. 3. Electrons from II are used to backfill I chlorophyll that lost electrons to NADPH + H+.H+. 4. Water is split by II to fill electrons lost to I by stealing electrons from hydrogen.

16. 3. Outcomes

17. The ATP and NADPH + H +.  sent to chloroplast stroma and are used to energize CO 2 (via ATP) & add hydrogen (via NADPH + H +.) The O2 O2 to the stomata to be expelled or mitochondria Do plants need to keep expelling O2 O2 for their benefit? Or yours?

18. D. Light Independent Reactions 1. Where

19. The eight step process (Calvin cycle, the light independent reactions, or the DARK reactions) is in the chloroplast’s stroma Figure 6.3

20. 2. Steps

21. Figure 6.8 Light Independent Reaction Steps

22. 1. Rubisco attaches 3CO 2 to RuBP 2. Requires 6ATP and 6NADPH + H+ H+ to make 6G3P 3. Separate 1G3P and hold in reserve 4. Rearrange other 5G3P back into RuBP requiring 3ATP 5. Repeat as long as you have enough ???? 1Glucose requires18ATP +12NADPH + H +.

23. 3. Outcomes What to do with the glucose?

24. E. Alternative Strategies 1. Photorespiration

25. 2. C3 C3 Plants

26. Rubisco can also bind to O2 O2 (Photorespiration) C3 C3 plants go senescentrice, wheat, some grasses, and soybean Figure 6.10

27. 3. C4 C4 Plants

28. C4 C4 plants turn CO 2 into acid molecules then break up to give CO 2 to Rubisco sugarcane, corn, and other grasses Figure 6.12

29. 4. CAM Plants

30. CAM plants completely separate light from dark reactions cactus, pineapples, and succulents Figure 6.13

31. Comparing C3 C3 with C4 C4 and CAM leave structures. Figure 6.11

32. Learning is the key to growing.