1. IMPORTANT “PLAYERS” IN PHOTOSYNTHESIS Electrons CO 2 H 2 O Sunlight (Photons) Electrons CO 2 H2OH2O Sunlight (Photons)

2. Electron Carriers (Shuttle buses) NADPH ATP, ADP, P Photosystems I & II Electron Carriers (Shuttle buses) NADPH ATP, ADP, P Photosystems I & II

3. Where is all this happening? The Chloroplast 2 parts-----1) Thylakoid membranes- - Stacks of thylakoids are grana 2) Matrix--The soupy inside of the chloroplast The Chloroplast 2 parts-----1) Thylakoid membranes- - Stacks of thylakoids are grana 2) Matrix--The soupy inside of the chloroplast

5. Photosynthesis-->2 Stages I. Light Reaction-->4 parts II. “Dark” Reaction-->4 steps I. Light Reaction-->4 parts II. “Dark” Reaction-->4 steps

6. Light Reaction 1) Light Absorption 2) Electron Transport 3) Oxygen Production 4) ATP formation 1) Light Absorption 2) Electron Transport 3) Oxygen Production 4) ATP formation

7. 1) Light Absorption Light is absorbed by a photosystem on the thylakoid membranes

8. (A photosystem contains clusters of chlorophyll molecules & accessory pigments)

9. The electrons of the chlorophyll are excited by sunlight and stripped off, raising them to a higher energy level (To do work) where they are passed to electron carrier molecules

11. 2) Electron Transport The high energy electrons (The excited ones) are passed along a series of electron carriers (proteins in the membrane) The carriers are known as the ETC (Electron Transport Chain) The high energy electrons (The excited ones) are passed along a series of electron carriers (proteins in the membrane) The carriers are known as the ETC (Electron Transport Chain)

13. At the end of the ETC, the high energy electrons are passed to their final destination NADP+

14. NADP+ + H+ + 2e- --->NADPH (NADPH is our carrier molecule, it carries electrons e- and Hydrogens H+)

15. 3) Oxygen Production The electrons that were stripped from the chlorophyll are paid back to the original chlorophyll molecule, from the splitting of H2O. (Photolysis) 2H20---> O2 + 4H+ + 4e-s The electrons that were stripped from the chlorophyll are paid back to the original chlorophyll molecule, from the splitting of H2O. (Photolysis) 2H20---> O2 + 4H+ + 4e-s

17. 4) ATP Formation When H 2 O is split, the H+’s are released inside of the thylakoid membrane. As e-’s are passed from chlorophyll to NADP+, more H+’s are pumped across the membrane. The inside becomes more positively charged. When H 2 O is split, the H+’s are released inside of the thylakoid membrane. As e-’s are passed from chlorophyll to NADP+, more H+’s are pumped across the membrane. The inside becomes more positively charged.

18. This Condition sets the stage for the chemiosmosis of H+ ions. (high-->low) H+ ions can pass through a special protein enzyme port (ATP Synthase) that attaches a phosphate to ADP forming ATP This Condition sets the stage for the chemiosmosis of H+ ions. (high-->low) H+ ions can pass through a special protein enzyme port (ATP Synthase) that attaches a phosphate to ADP forming ATP

23. ATP SYNTHASE

26. The Dark Reaction (Calvin Cycle) Step 1 3 CO2 molecules enter the cycle Each join with a 5 carbon RUBP and split-->Into 6 3 carbon PGA 3 CO2 molecules enter the cycle Each join with a 5 carbon RUBP and split-->Into 6 3 carbon PGA

27. Calvin cycle Step 2 The 6 molecules of PGA change into 6 molecules of PGAL (ATP & NADPH is used for this) 1 PGAL is used to make glucose The 6 molecules of PGA change into 6 molecules of PGAL (ATP & NADPH is used for this) 1 PGAL is used to make glucose

28. Step 3 Regeneration of RUBP The remaining 5 are used to make RUBP (A 5 carbon molecule) RUBP is regenerated by re- arranging the remaining 5 PGALS The remaining 5 are used to make RUBP (A 5 carbon molecule) RUBP is regenerated by re- arranging the remaining 5 PGALS