Chp Photosynthesis

LE 10-2 Plants Unicellular protist Multicellular algaeCyanobacteria Purple sulfur bacteria 10 µm 1.5 µm 40 µm

LE 10-3 Leaf cross section Vein Mesophyll Stomata CO 2 O2O2 Mesophyll cell Chloroplast 5 µm Outer membrane Intermembrane space Inner membrane Thylakoid space Thylakoid GranumStroma 1 µm

LE 10-7 Chloroplast Light Reflected light Absorbed light Transmitted light Granum

LE 10-6 Visible light Gamma rays X-rays UV Infrared Micro- waves Radio waves 10 –5 nm 10 –3 nm 1 nm 10 3 nm10 6 nm 1 m (10 9 nm) 10 3 m nm Longer wavelength Lower energy Shorter wavelength Higher energy Activity: Light and Pigments

LE 10-8a White light Refracting prism Chlorophyll solution Photoelectric tube Galvanometer The high transmittance (low absorption) reading indicates that chlorophyll absorbs very little green light. Green light Slit moves to pass light of selected wavelength 0 100

LE 10-8b White light Refracting prism Chlorophyll solution Photoelectric tube The low transmittance (high absorption) reading indicates that chlorophyll absorbs most blue light. Blue light Slit moves to pass light of selected wavelength 0 100

LE 10-9a Chlorophyll a Chlorophyll b Carotenoids Wavelength of light (nm) Absorption spectra Absorption of light by chloroplast pigments

LE 10-9b Action spectrum Rate of photo- synthesis (measured by O 2 release)

LE 10-4 Reactants: Products: 6 CO 2 12 H 2 O C 6 H 12 O 6 6 H 2 O 6 O 2

LE 10-5_3 H2OH2O LIGHT REACTIONS Chloroplast Light ATP NADPH O2O2 NADP + CO 2 ADP P + i CALVIN CYCLE [CH 2 O] (sugar) Activity: Overview of Photosynthesis

LE ATP Photosystem II e–e– e–e– e–e– e–e– Mill makes ATP e–e– e–e– e–e– Photon Photosystem I Photon NADPH

LE Thylakoid Photon Light-harvesting complexes Photosystem Reaction center STROMA Primary electron acceptor e–e– Transfer of energy Special chlorophyll a molecules Pigment molecules THYLAKOID SPACE (INTERIOR OF THYLAKOID) Thylakoid membrane

LE 10-13_5 Light P680 e–e– Photosystem II (PS II) Primary acceptor [CH 2 O] (sugar) NADPH ATP ADP CALVIN CYCLE LIGHT REACTIONS NADP + Light H2OH2O CO 2 Energy of electrons O2O2 e–e– e–e– + 2 H + H2OH2O O2O2 1/21/2 Pq Cytochrome complex Electron transport chain Pc ATP P700 e–e– Primary acceptor Photosystem I (PS I) e–e– e–e– Electron Transport chain NADP + reductase Fd NADP + NADPH + H H + Light

LE STROMA (Low H + concentration) Light Photosystem II Cytochrome complex 2 H + Light Photosystem I NADP + reductase Fd Pc Pq H2OH2O O2O2 +2 H + 1/21/2 2 H + NADP + + 2H + + H + NADPH To Calvin cycle THYLAKOID SPACE (High H + concentration) STROMA (Low H + concentration) Thylakoid membrane ATP synthase ATP ADP + P H+H+ i [CH 2 O] (sugar) O2O2 NADPH ATP ADP NADP + CO 2 H2OH2O LIGHT REACTIONS CALVIN CYCLE Light

LE MITOCHONDRION STRUCTURE Intermembrane space Membrane Electron transport chain Mitochondrion Chloroplast CHLOROPLAST STRUCTURE Thylakoid space Stroma ATP Matrix ATP synthase Key H+H+ Diffusion ADP +P H+H+ i Higher [H + ] Lower [H + ] Activity: Light Reactions

LE Photosystem I Photosystem II ATP Pc Fd Cytochrome complex Pq Primary acceptor Fd NADP + reductase NADP + NADPH Primary acceptor

LE 10-18_3 [CH 2 O] (sugar) O2O2 NADPH ATP ADP NADP + CO 2 H2OH2O LIGHT REACTIONS CALVIN CYCLE Light Input CO 2 (Entering one at a time) Rubisco 3PP Short-lived intermediate Phase 1: Carbon fixation 6 P 3-Phosphoglycerate 6 ATP 6 ADP CALVIN CYCLE 3 PP Ribulose bisphosphate (RuBP) 3 6 NADP NADPH P i 6P 1,3-Bisphosphoglycerate P 6 P Glyceraldehyde-3-phosphate (G3P) P1 G3P (a sugar) Output Phase 2: Reduction Glucose and other organic compounds 3 3 ADP ATP Phase 3: Regeneration of the CO 2 acceptor (RuBP) P 5 G3P Activity: Calvin Cycle

LE Photosynthetic cells of C 4 plant leaf Mesophyll cell Bundle- sheath cell Vein (vascular tissue) C 4 leaf anatomy Stoma Bundle- sheath cell Pyruvate (3 C) CO 2 Sugar Vascular tissue CALVIN CYCLE PEP (3 C) ATP ADP Malate (4 C) Oxaloacetate (4 C) The C 4 pathway CO 2 PEP carboxylase Mesophyll cell

LE Bundle- sheath cell Mesophyll cell Organic acid C4C4 CO 2 CALVIN CYCLE SugarcanePineapple Organic acids release CO 2 to Calvin cycle CO 2 incorporated into four-carbon organic acids (carbon fixation) Organic acid CAM CO 2 CALVIN CYCLE Sugar Spatial separation of stepsTemporal separation of steps Sugar Day Night Activity: Phtosyn. in Dry Climates

LE Light CO 2 H2OH2O Light reactionsCalvin cycle NADP + RuBP G3P ATP Photosystem II Electron transport chain Photosystem I O2O2 Chloroplast NADPH ADP +P i 3-Phosphoglycerate Starch (storage) Amino acids Fatty acids Sucrose (export)