Chapter 10Overview: The Process That Feeds the BiospherePowerPoint PresentationSlide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Concept 10.1: Photosynthesis converts light energy to the chemical energy of foodChloroplasts: The Sites of Photosynthesis in PlantsSlide 15Slide 16Slide 17Slide 18Tracking Atoms Through Photosynthesis: Scientific InquiryThe Splitting of WaterSlide 21Photosynthesis as a Redox ProcessThe Two Stages of Photosynthesis: A PreviewSlide 24Slide 25Slide 26Slide 27Slide 28Concept 10.2: The light reactions convert solar energy to the chemical energy of ATP and NADPHThe Nature of SunlightSlide 31Slide 32Photosynthetic Pigments: The Light ReceptorsSlide 34Slide 35Slide 36Slide 37Slide 38Slide 39Slide 40Slide 41Excitation of Chlorophyll by LightSlide 43A Photosystem: A Reaction-Center Complex Associated with Light-Harvesting ComplexesSlide 45Slide 46Slide 47Slide 48Linear Electron FlowSlide 50Slide 51Slide 52Slide 53Slide 54Slide 55Slide 56Slide 57Slide 58Slide 59Slide 60Cyclic Electron FlowSlide 62Slide 63A Comparison of Chemiosmosis in Chloroplasts and MitochondriaSlide 65Slide 66Slide 67Slide 68Concept 10.3: The Calvin cycle uses ATP and NADPH to convert CO2 to sugarSlide 70Slide 71Slide 72Slide 73Concept 10.4: Alternative mechanisms of carbon fixation have evolved in hot, arid climatesPhotorespiration: An Evolutionary Relic?Slide 76C4 PlantsSlide 78Slide 79Slide 80CAM PlantsSlide 82The Importance of Photosynthesis: A ReviewSlide 84Slide 85Slide 86Slide 87Slide 88Slide 89You should now be able to:Slide 91Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsPowerPoint® Lecture Presentations for Biology Eighth EditionNeil Campbell and Jane ReeceLectures by Chris Romero, updated by Erin Barley with contributions from Joan Sharp Chapter 10Chapter 10PhotosynthesisOverview: The Process That Feeds the Biosphere•Photosynthesis is the process that converts solar energy into chemical energy•Directly or indirectly, photosynthesis nourishes almost the entire living worldCopyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings•Autotrophs sustain themselves without eating anything derived from other organisms•Autotrophs are the producers of the biosphere, producing organic molecules from CO2 and other inorganic molecules•Almost all plants are photoautotrophs, using the energy of sunlight to make organic molecules from H2O and CO2Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsFig. 10-1•Photosynthesis occurs in plants, algae, certain other protists, and some prokaryotes•These organisms feed not only themselves but also most of the living worldBioFlix: PhotosynthesisBioFlix: PhotosynthesisCopyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsFig. 10-2(a) Plants(c) Unicellular protist10 µm1.5 µm40 µm(d) Cyanobacteria(e) Purple sulfur bacteria(b) Multicellular algaFig. 10-2a(a) PlantsFig. 10-2b(b) Multicellular algaFig. 10-2c(c) Unicellular protist10 µmFig. 10-2d40 µm(d) CyanobacteriaFig. 10-2e1.5 µm(e) Purple sulfur bacteria•Heterotrophs obtain their organic material from other organisms•Heterotrophs are the consumers of the biosphere•Almost all heterotrophs, including humans, depend on photoautotrophs for food and O2Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsConcept 10.1: Photosynthesis converts light energy to the chemical energy of food•Chloroplasts are structurally similar to and likely evolved from photosynthetic bacteria •The structural organization of these cells allows for the chemical reactions of photosynthesisCopyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsChloroplasts: The Sites of Photosynthesis in Plants•Leaves are the major locations of photosynthesis•Their green color is from chlorophyll, the green pigment within chloroplasts•Light energy absorbed by chlorophyll drives the synthesis of organic molecules in the chloroplast•CO2 enters and O2 exits the leaf through microscopic pores called stomataCopyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings•Chloroplasts are found mainly in cells of the mesophyll, the interior tissue of the leaf•A typical mesophyll cell has 30–40 chloroplasts•The chlorophyll is in the membranes of thylakoids (connected sacs in the chloroplast); thylakoids may be stacked in columns called grana•Chloroplasts also contain stroma, a dense fluid Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsFig. 10-3Leaf cross sectionVeinMesophyllStomataCO2O2ChloroplastMesophyll cellOutermembraneIntermembranespace5 µmInnermembraneThylakoidspaceThylakoidGranumStroma1 µmFig. 10-3a5 µmMesophyll cellStomataCO2O2ChloroplastMesophyllVeinLeaf cross sectionFig. 10-3b1 µmThylakoidspaceChloroplastGranumIntermembranespaceInnermembraneOutermembraneStromaThylakoidTracking Atoms Through Photosynthesis: Scientific Inquiry•Photosynthesis can be summarized as the following equation:6 CO2 + 12 H2O + Light energy  C6H12O6 + 6 O2 + 6 H2O Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsThe Splitting of Water•Chloroplasts split H2O into hydrogen and oxygen, incorporating the electrons of hydrogen into sugar moleculesCopyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsReactants:Fig. 10-46 CO2Products:12 H2O6 O26 H2OC6H12O6Photosynthesis as a Redox Process•Photosynthesis is a redox process in which H2O is oxidized and CO2 is reducedCopyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsThe Two Stages of Photosynthesis: A Preview•Photosynthesis consists of the light reactions (the photo part) and Calvin cycle (the synthesis part)•The light reactions (in the thylakoids):–Split H2O–Release O2–Reduce NADP+ to NADPH–Generate ATP from ADP by photophosphorylationCopyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings•The Calvin cycle (in the stroma) forms sugar from CO2, using ATP and NADPH•The Calvin cycle begins with carbon fixation, incorporating CO2 into organic moleculesCopyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin CummingsLightFig. 10-5-1H2OChloroplastLightReactionsNADP+PADPi+LightFig. 10-5-2H2OChloroplastLightReactionsNADP+PADPi+ATPNADPHO2LightFig.