07 Lecture Animation Ppt
- 1. Photosynthesis Chapter 7: pp. 117-132 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. thylakoid membrane NADP + NADP ATP Calvin Cycle reactions Light reactions Solar energy H 2 O CO 2 CH 2 O O 2 stroma thylakoid membrane NADP + ADP + P
- 2. Outline Photosynthetic Organisms Photosynthetic Process Plants as Solar Energy Converters Photosynthesis Light Reactions Noncyclic Cyclic Calvin Cycle Reactions Fixation of Carbon Dioxide C4 CAM
- 3. Photosynthetic Organisms All life on Earth depends on a star 93 million miles away (solar energy) Photosynthetic organisms (algae, plants, and cyanobacteria) transform solar energy into carbohydrates Called autotrophs because they produce their own food. Photosynthesis: A process that captures solar energy Transforms solar energy into chemical energy Energy ends up stored in a carbohydrate Photosynthesizers produce all food energy Only 42% of sun’s energy directed towards Earth reaches surface Of this, only 2% is captured by photosynthesizers Of this, only a tiny portion results in biomass
- 4. Photosynthetic Organisms mosses garden plants trees cyanobacteria Euglena diatoms kelp Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. (Moss): © Steven P. Lynch; (Trees): © Digital Vision/PunchStock; (Kelp): © Chuck Davis/Stone/Getty Images; (Cyanobacteria): © Sherman Thomas/Visuals Unlimited; (Diatoms): © Ed Reschke/Peter Arnold; (Euglena): © T.E. Adams/Visuals Unlimited; (Sunflower): © Royalty-Free/Corbis
- 5. Photosynthesis Photosynthesis takes place in the green portions of plants Leaf of flowering plant contains mesophyll tissue Cells containing chloroplasts Specialized to carry on photosynthesis Raw materials for photosynthesis are carbon dioxide and water Roots absorb water that moves up vascular tissue Carbon dioxide enters a leaf through small openings called stomata Diffuses into chloroplasts in mesophyll cells In stroma, CO 2 combined with H 2 O to form C 6 H 12 O 6 (sugar) Energy supplied by light Chlorophyll and other pigments absorbs solar energy and energize electrons prior to reduction of CO2 to a carbohydrate
- 6. Leaves and Photosynthesis Grana Chloroplast Leaf cross section granum independent thylakoid in a granum mesophyll lower epidermis upper epidermis cuticle leaf vein outer membrane inner membrane thylakoid space thylakoid membrane overlapping thylakoid in a granum CO 2 O 2 stoma stroma stroma 37,000 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © Dr. George Chapman/Visuals Unlimited
- 7. Photosynthetic Pigments Pigments: Chemicals that absorb some colors in rainbow more than others Colors least absorbed reflected/transmitted most Absorption Spectra Pigments found in chlorophyll absorb various portions of visible light Graph showing relative absorption of the various colors of the rainbow Chlorophyll is green because it absorbs much of the reds and blues of white light
- 8. Photosynthetic Pigments Wavelengths (nm) Increasing wavelength a. The electromagnetic spectrum includes visible light. b. Absorption spectrum of photosynthetic pigments. Increasing energy Gamma rays X rays UV Infrared Micro- waves Radio waves visible light 500 600 750 Wavelengths (nm) 380 500 600 750 chlorophyll a chlorophyll b carotenoids Relative Absorption Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
- 9. Animation Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.
- 10. Photosynthesis Releases Oxygen Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © B. Runk/S. Schoenberger/Grant Heilman Photography
- 11. Photosynthetic Reactions: Two Sets of Reaction Light Reaction – takes place only in the presence of light They are the energy‑capturing reactions Chlorophyll absorbs solar energy This energizes electrons Electrons move down electron transport chain Pumps H + into thylakoids Used to make ATP out of ADP and NADPH out of NADP Calvin Cycle Reaction takes place in stroma CO 2 is reduced to a carbohydrate Use ATP and NADPH produced carbohydrate They are synthetic reactions
- 12. Photosynthesis Overview Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. thylakoid membrane ADP + P NADP + NADP ATP Calvin Cycle reactions Light reactions Solar energy H 2 O CO 2 CH 2 O O 2 stroma
- 13. Photosynthetic Reactions: The Light Reactions Light reactions consist of two alternate electron pathways: Noncyclic electron pathway Cyclic electron pathway Capture light energy with photosystems Pigment complex helps collect solar energy like an antenna Occur in the thylakoid membranes Both pathways produce ATP The noncyclic pathway also produces NADPH
- 14. Light Reactions: The Noncyclic Electron Pathway Takes place in thylakoid membrane Uses two photosystems, PS-I and PS-II PS II captures light energy Causes an electron to be ejected from the reaction center (chlorophyll a ) Electron travels down electron transport chain to PS-I Replaced with an electron from water Which causes H + to concentrate in thylakoid chambers Which causes ATP production PS-I captures light energy and ejects an electron Transferred permanently to a molecule of NADP + Causes NADPH production
- 15. Light Reactions: Noncyclic Electron Pathway NADPH 2H + H 2 O electron acceptor NADP + H + pigment complex pigment complex reaction center reaction center sun sun electron transport chain (ETC) Photosystem II Photosystem I NADPH thylakoid membrane solar energy Calvin cycle ATP Calvin cycle reactions energy level CO 2 CH 2 O Light reactions O 2 1 2 ADP+ P NADP + e - e - e e e e - e - electron acceptor CH 2 O H 2 O CO 2 O 2 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
- 16. Animation Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.
- 17. Animation Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.
- 18. Light Reactions: The Cyclic Electron Pathway Uses only photosystem I (PS-I) Begins when PS I complex absorbs solar energy Electron ejected from reaction center Travels down electron transport chain Causes H + to concentrate in thylakoid chambers Which causes ATP production Electron returns to PS-I (cyclic) Pathway only results in ATP production
- 19. Organization of the Thylakoid Membrane PS II: Consists of a pigment complex and electron-acceptors Adjacent to an enzyme that oxidizes water Oxygen is released as a gas Electron transport chain: Consists of cytochrome complexes Carries electrons between PS II and PS I Also pump H + from the stroma into thylakoid space PS I: Has a pigment complex and electron acceptors Adjacent to enzyme that reduces NADP + to NADPH ATP synthase complex: Has a channel for H + flow Which drives ATP synthase to join ADP and P i
- 20. Organization of a Thylakoid stroma P NADPH Calvin cycle reactions ATP thylakoid photosystem II Stroma NADP reductase NADP + H + H + Pq H + H + ATP synthase chemiosmosis electron transport chain photosystem I granum thylakoid membrane thylakoid space stroma ATP NADPH +ADP P O 2 2 + 2 1 Thylakoid space e - H 2 O CO 2 O 2 CH 2 O solar energy thylakoid membrane Light reactions ADP + NADP + NADP + NADP + NADP + e - e - H + H + H + H + H + e - H 2 O Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
- 21. Animation Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.
- 22. ATP Production Thylakoid space acts as a reservoir for hydrogen ions (H + ) Each time water is oxidized, two H + remain in the thylakoid space Electrons yield energy Used to pump H + across thylakoid membrane Move from stroma into the thylakoid space Flow of H + back across thylakoid membrane Energizes ATP synthase Enzymatically produces ATP from ADP + P i This method of producing ATP is called chemiosmosis
- 23. Ecology Focus : Tropical Rain Forests Equatorial; Temp>26ºC; Rainfall>200cm & uniform Most plants woody; many vines and epiphytes; little or no undergrowth Contribute greatly to CO 2 uptake, slowing global warming Development has reduced them from 14% to 6% of Earth’s surface Deforestation adds 20-30% of atmospheric CO 2 , but also removes CO 2 sink Increasing temps also reduce productivity
- 24. Ecology Focus : Global Warming and Tropical Rain Forests b. -0.5 0.5 1.5 2.5 3.5 4.5 5.5 1860 1940 minimum likely increase maximum likely increase 2020 2060 2100 Mean Global Temperature Change (°C) Y ear a. most probable temperature increase for 2 × CO 2 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © George Holton/Photo Researchers, Inc.
- 25. Calvin Cycle Reactions: Overview of C3 Photosynthesis A cyclical series of reactions Utilizes atmospheric carbon dioxide to produce carbohydrates Known as C3 photosynthesis Involves three stages: Carbon dioxide fixation Carbon dioxide reduction RuBP regeneration
- 26. Calvin Cycle Reactions: Carbon Dioxide Fixation CO 2 is attached to 5-carbon RuBP molecule Result in a 6-carbon molecule This splits into two 3-carbon molecules (3PG) Reaction accelerated by RuBP Carboxylase (Rubisco) CO 2 now “fixed” because it is part of a carbohydrate
- 27. The Calvin Cycle: Fixation of CO 2 RuBP ribulose-1,5-bisphosphate 3PG 3-phosphoglycerate BPG 1,3-bisphosphoglycerate G3P glyceraldehyde-3-phosphate Metabolites of the Calvin Cycle These ATP and NADPH molecules were produced by the light reactions. 3 ADP + 3 P 6 ADP + 6 P These ATP molecules were produced by the light reactions. net gain of one G3 P Glucose CO 2 fixation CO2 reduction regeneration of RuBP intermediate 6 NADPH + 5 G3P C 3 3 RuBP C 5 6 G3P C 3 6 BPG C 3 3 CO 2 Other organic molecules 6 NADPH 3 ATP 6 ATP Calvin cycle 6 3PG C 3 3 C 6 CH 2 O stroma H 2 O CO 2 ADP + P NADPH NADP + ATP O 2 2 solar energy Light reactions Calvin cycle Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
- 28. Calvin Cycle Reactions: Carbon Dioxide Reduction 3PG reduced to BPG BPG then reduced to G3P Utilizes NADPH and some ATP produced in light reactions
- 29. The Calvin Cycle: Reduction of CO 2 NADPH NADP + ATP 3PG G3P BPG ADP + P As 3PG becomes G3P, ATP becomes ADP + and NADPH becomes NADP + P Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
- 30. Calvin Cycle Reactions: Regeneration of RuBP RuBP used in CO 2 fixation must be replaced Every three turns of Calvin Cycle, Five G3P (a 3-carbon molecule) used To remake three RuBP (a 5-carbon molecule) 5 X 3 = 3 X 5
- 31. The Calvin Cycle: Regeneration of RuBP As five molecules of G3P become three molecules of RuBP, three molecules of ATP become three molecules of ADP + . 3 ATP 5 G3P 3 RuBP 3 ADP + P P Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
- 32. Importance of Calvin Cycle G3P (glyceraldehyde-3-phosphate) can be converted to many other molecules The hydrocarbon skeleton of G3P can form Fatty acids and glycerol to make plant oils Glucose phosphate (simple sugar) Fructose (which with glucose = sucrose) Starch and cellulose Amino acids
- 33. Animation Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.
- 34. Animation Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.
- 35. Fate of G3P G3P starch fatty acid synthesis glucose phosphate + fructose phosphate cellulose sucrose amino acid synthesis10 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
- 36. C 4 Photosynthesis In hot, dry climates Stomata must close to avoid wilting CO 2 decreases and O 2 increases O 2 starts combining with RuBP instead of CO 2 Photorespiration, a problem solve in C 4 plants In C 4 plants Fix CO 2 to PEP a C 3 molecule The result is oxaloacetate, a C 4 molecule In hot & dry climates Avoid photorespiration Net productivity about 2-3 times C 3 plants In cool, moist, can’t compete with C 3
- 37. Chloroplast Distribution in C 4 vs. C 3 Plants C 3 Plant C 4 Plant bundle sheath cell bundle sheath cell mesophyll cells vein vein stoma stoma Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
- 38. CO 2 Fixation in C 4 vs. C 3 Plants Calvin cycle CO 2 G3P 3PG RuBP mesophyll cell CO 2 CO 2 C 4 G3 bundle sheath cell mesophyll cell a. CO 2 fixation in a C 3 plant, blue columbine, Aquilegia caerulea b. CO 2 fixation in a C 4 plant, corn, Zea mays Calvin cycle Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. b: © Nigel Cattlin/Photo Researchers, Inc.
- 39. CAM Photosynthesis Crassulacean-Acid Metabolism CAM plants partition carbon fixation by time During the night CAM plants fix CO 2 Forms C 4 molecules, Stored in large vacuoles During daylight NADPH and ATP are available Stomata closed for water conservation C 4 molecules release CO 2 to Calvin cycle
- 40. CO 2 Fixation in a CAM Plant Calvin cycle CO 2 CO 2 C 4 G3P CO 2 fixation in a CAM plant, pineapple, Ananas comosus night day Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © S. Alden/PhotoLink/Getty Images.
- 41. Animation Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.
- 42. Climatic Adaptation: Photosynthesis Each method of photosynthesis has Advantages and disadvantages Depends on the climate C 4 plants most adapted to: High light intensities High temperatures Limited rainfall C 3 plants better adapted to Cold (below 25°C) High moisture CAM plants better adapted to extreme aridity CAM occurs in 23 families of flowering plants Also found among nonflowering plants
- 43. Review Flowering Plants Photosynthetic Pigments Photosynthesis Light Reactions Noncyclic Cyclic Carbon Fixation Calvin Cycle Reactions C4 CAM
- 44. Photosynthesis Chapter 7: pp. 117-132 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. thylakoid membrane NADP + NADP ATP Calvin Cycle reactions Light reactions Solar energy H 2 O CO 2 CH 2 O O 2 stroma thylakoid membrane NADP + ADP + P