PhotosynthesisPhotoautotrophsCarbon and Energy SourcesPhotoautotrophsT.E. Englemann’s ExperimentT.E. Englemann’s ExperimentSlide 7Slide 8Slide 9Linked ProcessesFocusing in on the location of photosynthesis in a plantLocation and structure of chlorophyll molecules in plantsPhotosynthesis EquationTwo Stages of PhotosynthesisSunlight EnergyElectromagnetic SpectrumVisible LightPhotonsPigmentsPigments in PhotosynthesisPigments in a PhotosystemLight-Dependent ReactionsPhotosystem Function: Harvester PigmentsPhotosystem Function: Reaction CenterCyclic Electron FlowElectron Transport SystemSlide 27Energy ChangesNoncyclic Electron FlowFigure 10.4 An overview of photosynthesis: cooperation of the light reactions and the Calvin cycle (Layer 1)Figure 10.4 An overview of photosynthesis: cooperation of the light reactions and the Calvin cycle (Layer 2)Light-Independent ReactionsCalvin-Benson CycleMelvin CalvinThe Calvin cycle (Layer 1)The Calvin cycle (Layer 2)The Calvin cycle (Layer 3)Using the Products of PhotosynthesisThe C3 PathwayPhotorespiration in C3 PlantsC4 PlantsFigure 10.18 C4 leaf anatomy and the C4 pathwayCAM PlantsFigure 10.19 C4 and CAM photosynthesis comparedFigure 10.20 A review of photosynthesisPhotosynthesisPhotosynthesisHow Plants Make Food from How Plants Make Food from Sunlight and Low Energy Sunlight and Low Energy MoleculesMoleculesPhotoautotrophsPhotoautotrophsPhotoautotrophsPhotoautotrophsCarbon source is carbon dioxideCarbon source is carbon dioxideEnergy source is sunlightEnergy source is sunlightHeterotrophsHeterotrophsGet carbon and energy by eating Get carbon and energy by eating autotrophs or one anotherautotrophs or one anotherCarbon and Energy Carbon and Energy SourcesSourcesPhotoautotrophs Photoautotrophs Capture sunlight energy and use it to Capture sunlight energy and use it to carry out photosynthesiscarry out photosynthesisPlantsPlantsSome bacteriaSome bacteriaMany protistansMany protistansT.E. Englemann’s T.E. Englemann’s Experiment Experiment Background Background Certain bacterial cells will move Certain bacterial cells will move toward places where oxygen toward places where oxygen concentration is highconcentration is highPhotosynthesis produces oxygenPhotosynthesis produces oxygenT.E. Englemann’s T.E. Englemann’s ExperimentExperimentHypothesisHypothesisMovement of bacteria can be used to Movement of bacteria can be used to determine optimal light wavelengths determine optimal light wavelengths for photosynthesis for photosynthesisT.E. Englemann’s T.E. Englemann’s ExperimentExperimentMethodMethodAlgal strand placed on microscope Algal strand placed on microscope slide and illuminated by light of slide and illuminated by light of varying wavelengthsvarying wavelengthsOxygen-requiring bacteria placed on Oxygen-requiring bacteria placed on same slidesame slideT.E. Englemann’s T.E. Englemann’s ExperimentExperimentT.E. Englemann’s T.E. Englemann’s ExperimentExperimentResults Results Bacteria congregated where red and Bacteria congregated where red and violet wavelengths illuminated algaviolet wavelengths illuminated alga ConclusionConclusionBacteria moved to where algal cells Bacteria moved to where algal cells released more oxygen--areas released more oxygen--areas illuminated by the most effective illuminated by the most effective light for photosynthesislight for photosynthesisLinked ProcessesLinked ProcessesPhotosynthesisPhotosynthesisEnergy-storing Energy-storing pathway pathway Releases oxygenReleases oxygenRequires carbon Requires carbon dioxidedioxideAerobic RespirationAerobic RespirationEnergy-releasing Energy-releasing pathwaypathwayRequires oxygenRequires oxygenReleases carbon Releases carbon dioxidedioxideFocusing in on the location of photosynthesis in a plantFocusing in on the location of photosynthesis in a plantLocation and structure of chlorophyll molecules in plantsLocation and structure of chlorophyll molecules in plantsPhotosynthesis EquationPhotosynthesis Equation12H2O + 6CO26O2 + C6H12O6 + 6H2Owater carbon dioxideoxygen glucosewaterLIGHT ENERGYTwo Stages of Two Stages of PhotosynthesisPhotosynthesissunlight water uptake carbon dioxide uptakeATPADP + PiNADPHNADP+glucosePoxygen releaseLIGHT INDEPENDENT-REACTIONSLIGHT DEPENDENT-REACTIONSnew waterContinual input of solar energy into Continual input of solar energy into Earth’s atmosphere Earth’s atmosphere Almost 1/3 is reflected back into Almost 1/3 is reflected back into spacespaceOf the energy that reaches Earth’s Of the energy that reaches Earth’s surface, about 1% is intercepted by surface, about 1% is intercepted by photoautotrophsphotoautotrophsSunlight EnergySunlight EnergyElectromagnetic Electromagnetic Spectrum Spectrum Shortest Shortest Gamma raysGamma rayswavelength wavelength X-raysX-raysUV radiationUV radiationVisible lightVisible lightInfrared radiationInfrared radiationMicrowavesMicrowavesLongestLongestRadio wavesRadio waveswavelengthwavelengthVisible Light Visible Light Wavelengths humans perceive as Wavelengths humans perceive as different colorsdifferent colorsViolet (380 nm) to red (750 nm) Violet (380 nm) to red (750 nm) Longer wavelengths, lower energyLonger wavelengths, lower energyPhotonsPhotonsPackets of light energyPackets of light energyEach type of photon has fixed Each type of photon has fixed amount of energyamount of energyPhotons having most energy travel Photons having most energy travel as shortest wavelength (blue-green as shortest wavelength (blue-green light)light)PigmentsPigmentsLight-absorbing Light-absorbing moleculesmoleculesAbsorb some Absorb some wavelengths and wavelengths and transmit otherstransmit othersColor you see are Color you see are the wavelengths the wavelengths NOT absorbed NOT absorbed Wavelength (nanometers)chlorophyll bchlorophyll aPigments in Pigments in PhotosynthesisPhotosynthesisBacteriaBacteriaPigments in plasma membranesPigments in plasma membranesPlantsPlantsPigments embedded in thylakoid Pigments embedded in thylakoid membrane systemmembrane systemPigments and proteins organized into Pigments and proteins organized into photosystemsphotosystemsPhotosystems located next to electron Photosystems located next to electron transport systemstransport systemsPigments in a Pigments in a PhotosystemPhotosystemreaction center (a specialized chlorophyll a molecule)Pigments