绿色植物制造了有机物.ppt

1. Light Reaction (Electron Flow) Occurs in the Thylakoid membranes During the light reaction, there are two possible routes for electron flow. A. Cyclic Electron Flow B. Noncyclic Electron Flow A. Cyclic Electron Flow Occurs in the thylakoid membrane. Uses Photosystem I only P700 reaction center- chlorophyll a Uses Electron Transport Chain (ETC) Generates ATP only ADP + ATP P A. Cyclic Electron Flow P700 Primary Electron Acceptor e- e- e- e- ATP produced by ETC Photosystem I Accessory Pigments SUN Photons B. Noncyclic Electron Flow Occurs in the thylakoid membrane Uses PS II and PS I P680 rxn center (PSII) - chlorophyll a P700 rxn center (PS I) - chlorophyll a Uses Electron Transport Chain (ETC) Generates O2, ATP and NADPH B. Noncyclic Electron Flow P700 Photosystem I P680 Photosystem II Primary Electron Acceptor Primary Electron Acceptor ETC Enzyme Reaction H2O 1/2O2 + 2H+ ATP NADPH Photon 2e- 2e- 2e- 2e- 2e- SUN Photon B. Noncyclic Electron Flow ADP + ? ATP NADP+ + H ?? NADPH Oxygen comes from the splitting of H2O, not CO2 H2O ? 1/2 O2 + 2H+ (Reduced) P (Reduced) (Oxidized) Chemiosmosis Powers ATP synthesis. Located in the thylakoid membranes. Uses ETC and ATP synthase (enzyme) to make ATP. Photophosphorylation: addition of phosphate to ADP to make ATP. Chemiosmosis H+ H+ ATP Synthase H+ H+ H+ H+ H+ H+ high H+ concentration H+ ADP + P ATP PS II PS I E T C low H+ concentration H+ Thylakoid Space Thylakoid SUN (Proton Pumping) Calvin Cycle Carbon Fixation (light independent rxn). C3 plants (80% of plants on earth). Occurs in the stroma. Uses ATP and NADPH from light rxn. Uses CO2. To produce glucose: it takes 6 turns and uses 18 ATP and 12 NADPH. Chloroplast Granum Thylakoid Stroma Outer Membrane Inner Membrane Calvin Cycle (C3 fixation) 6CO2 6C-C-C-C-C-C 6C-C-C 6C-C-C 6C-C-C-C-C 12PGA RuBP 12G3P (unstable) 6NADPH 6NADPH 6ATP 6ATP 6ATP C-C-C-C-C-C Glucose (6C) (36C) (36C) (36C) (30C) (30C) (6C) 6C