1. PHOTOSYNTHESIS Photoautotrophism - using light energy to synthesize organic molecules. PLANTS GREEN ALGAE (Protists) MULTICELLULAR ALGAE CYANOBACTERIA PURPLE SULFUR BACTERIA

2. PHOTOSYNTHESIS The Basic Chemical Reaction 6 CO 2 12 H O 2 + C H O 6 6 12 6 H O 2 6 O 2 ++ Light Energy CO 2 + H2OH2OCH 2 O + O2O2 Light Energy

3. LIGHT REACTION Photophosphorylation LIGHT CHLOROPHYLL WATER SPLITTING Reactions H+H+ OO2O2 e-e- H + gradiente - transport chain Thylakoid

4. DARK REACTION Calvin-Benson Cycle H + gradiente - transport chain Thylakoid ATP NADPH Stroma CO 2 sugars Calvin Cycle

5. LIGHT REACTION Making ATP PHOTOSYSTEMS Cluster of pigment molecules

6. LIGHT REACTION Photosystem II LIGHT (a photon) Transfer of energy Primary electron acceptor The reaction-center chlorophyll in the first stage of this process is known as P680. Reaction center chlorophyll

7. LIGHT REACTION Photosystem II Photosystem I Electron Transport Chain to Make ATP 2e - P680P700 H2OH2O O Light 2e - + 2H +

8. Photosystem I P700 Light 2e - LIGHT REACTION NADP + Reductase NADPH Calvin-Benson Cycle

9. LIGHT REACTION OVERVIEW Thylakoid Space Stroma Photo system II H2OH2O O + 2H + 2H + ATP Synthase Photo system I ADP + P i ATP H+H+ NADPH Cytochrome Complex NADP + Reductase light

10. DARK REACTION Calvin-Benson Cycle 3 CO 2 Rubisco 1. CARBON FIXATION ATP 6 6 ADP P PP P NADPH 6 6 NADP + 6 PiPi G3P P PP RuBP ATP 3 3 ADP 2. REDUCTION 3. REGENRATION OF CO 2 ACCEPTOR 1 G3P INPUT OUTPUT 6 6 6 5 3

11. 1 Glyceraldehyde-3-phosphate CARBOHYDRATE SYNTHESIS OUTPUT Calvin-Benson Cycle P OH  glucose O OH CH 2 OH sucrose O O O

12. ALTERNATIVE MECHANSISMS OF CARBON FIXATION C 4 PlantsCrassulacean Acid Metabolism Mesophyll Cell CO 2 Vascular Tissue Calvin Cycle CO 2 PEP (3C) ATP (4C) (3C) Bundle Sheath Cell PEP Carboxylase sugar CO 2 Calvin Cycle Organic Acid CO 2 sugar Night Day

13. PHOTOSYNTHESIS Final Summary  Use of Light (energy), Water and CO 2  Final Products - - Oxygen and Sugars  Light Reactions require photons, produce ATP & NADPH  Dark Reactions depend on availability of ATP & NADPH  Dark Reactions produce carbohydrate precursors