Photosynthesis

1. An Overview of Photosynthesis & Respiration 2. Autotrophs and producers 3. Electromagnetic Spectrum & light energy 4. Chloroplasts: Structure and Function 5. Photosynthetic pigments 6. Chemical Reactions of Photosynthesis Outline - Photosynthesis

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings CO 2 H2OH2O Glucose O2O2 ATP Sunlight Photosynthesis Cellular respiration Heat –Respiration & Photosynthesis are Related

Energy to Drive Metabolism HETEROTROPHS  Consumers AUTOTROPHS  Producers Harvest sunlight Convert solar energy into chemical energy Examples of autotrophs Plants Algae Cyanobacteria

Increasing energy Increasing wavelength 0.1 nm 1 nm10 nm 1000 nm0.1 cm 1 cm 1 m100 m Gamma rays UV light X rays Infrared Radio waves 400 nm 430 nm 500 nm560 nm600 nm650 nm740 nm Visible light Electromagnetic Spectrum

Light Absorption During Photosynthesis W h it e L i gh t Sun

Carotenoids orange/yellow Chlorophylls green Pigments of Photosynthesis

Wavelength (nm) Amount of light absorption Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chlorophyll a Chlorophyll b Carotenoid Absorption Spectrum of Photosynthetic Pigments Chlorophyll a, Chlorophyll b & Carotenoids

Photosynthesis Occurs in Chloroplasts

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Photosynthesis is a redox process CO 2 is reduced H 2 O is oxidized Reduction Oxidation 6 O 2 6 CO 2  6 H 2 O C 6 H 12 O 6  Photosynthesis Equation

Fig. 10.6b (TEArt) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chloroplast Structure Thylakoid Granum Stroma

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Location of Photosynthesis Carbon Dioxide Used & Sugar Produced Water Used & Oxygen Produced

CO 2 H20H20 Stroma Thylakoid Reactions of Photosynthesis Light Harvesting Light- Dependent Reactions O2O2 Carbohydrates ADP NADPHATP NADP + Light Independent Reactions Sugar Building Calvin Cycle

Fig. 10.6a (TEArt) Chlorophyll molecules and Carotenoids in light-harvesting protein complex Thylakoid membrane Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Photosynthesis: Light Harvesting by Photosystems Reaction Center Chlorophyll Sun

Fig (TEArt) Electron Acceptor Photon Chlorophyll molecules Photosystem e-e- Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Reaction center chlorophyll Photosynthesis: Light Harvesting by Photosystems e-e-

Photosystem I Reduces NADP + e-e- Photosystem I

e-e- PSII Reaction Center Photosystem II Supplies Electrons to PSI

Photosystem II Water Splitting & Oxygen Production Photosystem II

e-e- Photosystem II Supplies Electrons to PSI H2OH2O O2O2 H+H+ H+H+ e-e- O O NADPH NADP e-e-

e-e- Photosystem II Supplies Electrons to PSI H+

Fig. 10.6b (TEArt) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Thylakoid Structure Thylakoid

Fig b (TEArt) Photosystem IIb 6 -f complexATP synthase H+H+ Photon Stroma Thylakoid space Q H2OH2O ATP ADP e-e- H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ 2H _ Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Stroma Chemiosomosis & ATP Synthesis in Chloroplasts

Fig (TEArt) Water- splitting enzyme Photon Ferredoxin Plastoquinone Photosystem II NADP + + H + b 6 -f complex NADP reductase b 6 -f complex Photosystem INADP reductase H2OH2O 2H + + O 2 H+H+ pC Q P 700 P 680 NADPH Fd Reaction center e–e– Plastocyanin 1 2 Excited reaction center e–e– e–e– e–e– Energy of electrons Reaction center __ Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Photosynthesis: Light Harvesting by Photosystems

Figure 7.8B e–e– ATP Photon Photosystem II Photosystem I NADPH e–e– e–e– e–e– e–e– e–e– e–e– Light Reactions Mechanical Analogy H 2 O provides electrons electron transport chain reduce NADPH ATP synthesized Oxygen released H2OH2O O 2 e -

Summary of Light Harvesting Reactions 1.H 2 O provides electrons for electron transport chains 2.NADP  reduced to NADPH 3.ATP synthesized by chemiosmosis 4.Oxygen released

1.Fixation 2. Reduction 3. Regeneration Sugar Building – The Calvin Cycle CO 2 P Glucose NADPH ATP Glyceraldehyde 3-phosphate RuBP 3-phospho glycerate Glyceraldehyde 3-phosphate RuBP

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings PHOTOSYNTHESIS REVIEW Figure 7.11 Light H2OH2O CO 2 NADP + Photosystem II Photosystem I Light Reactions ADP P + RUBP CALVIN CYCLE 3-PGA Stroma G3P NADPH ATP O2O2 Sugars Cellular respiration Cellulose Starch Other organic compounds Thylakoid membranes Chloroplast Reactants Products

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings CO 2 H2OH2O Glucose O2O2 ATP Sunlight Heat Importance of Photosynthesis Photosynthesis Cellular respiration

END Photosynthesis END Photosynthesis