PowerPoint PresentationSlide 2Part I: The “Pieces” of Photosynthesis7.1 What Is Photosynthesis?Englemann’s ExperimentPhotosynthesis and Cellular Respiration are Linked ProcessesSlide 7Where Atoms End UpAuthor Animation: PhotosynthesisSlide 10An Overview of Photosynthetic StructuresSlide 12StomataSlide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22An Overview of the Relationship Between the Light Reactions and the Calvin CycleSlide 24Author Animation: Reactions of Photosynthesis7.2 Light Reactions: How Is Light Energy Converted to Chemical Energy?Slide 27Slide 28Author Animation: Visible LightSlide 30Slide 31Insects can see/detect patterns using UV lightLight and Chloroplast PigmentsLoss of Chlorophyll Reveals Yellow Carotenoid PigmentsA Preview of Photosynthesis (take a deep breath…)Two Stages of PhotosynthesisPart II: The “Steps” of PhotosynthesisSlide 38Slide 39Slide 40Slide 41Author Animation: Light-Dependent ReactionsSlide 43Author Animation: ChemiosmosisEnergy Stored in a Water “Gradient” Can Be Used to Generate ElectricityOxygen Is a By-product of LIGHT Reactions7.3 The Calvin Cycle (DARK RXNS): How Is Chemical Energy Stored in Sugar Molecules?Slide 48Author Animation: Light Independent ReactionsSlide 507.4 Why Do Some Plants Use Alternate Pathways for Carbon Fixation?Slide 52The C4 PathwayThe CAM PathwayChapter 7Capturing Solar Energy: PhotosynthesisWhat happened to the dinosaurs?Part I: The “Pieces” of Photosynthesis7.1 What Is Photosynthesis?For most organisms, energy is derived from sunlight, either directly or indirectlyThose organisms that can directly trap sunlight do so by photosynthesis Process by which solar energy is trapped and stored as chemical energy in the bonds of a sugarEnglemann’s Experiment Certain bacterial cells will move toward places where oxygen concentration is highPhotosynthesis produces oxygen as a by-productNotice that the bacteria (white specks) concentrate in 2 separate color regions, where oxygen concentration is higherYouTube video (click me)Photosynthesis and Cellular Respiration are Linked ProcessesPhotosynthesis energy-storing pathway releases oxygen requires carbon dioxideAerobic Respiration energy-releasing pathway requires oxygen releases carbon dioxidePhotosynthesis and Cellular Respiration are Linked ProcessesWhere Atoms End UpProducts6O2C6H12O66H2OReactants12H2O 6CO2Water “splits”Author Animation: PhotosynthesisLeaves and chloroplasts are adaptations for photosynthesis– Chlorophyll-containing organelles called chloroplasts are concentrated in leaf cells– Chloroplasts are able to convert energy in sunlight into stored energy of sugars– Both the upper and lower surfaces of a leaf consist of a layer of transparent cells, the epidermis (skin largest organ in body)An Overview of Photosynthetic Structures Fig. 7-1cuticle(b) Internal leaf structureupperepidermismesophyllcellslowerepidermischloroplastsstomabundle sheath cellsvascular bundle(vein)stomaouter membraneinner membranethylakoidstromachannelinterconnectingthylakoids (d ) Chloroplast(a) Leaves(c) Mesophyll cell containing chloroplastsLeaves and chloroplasts are adaptations for photosynthesis (continued)– The outer surface of leaves are covered by the cuticle– transparent, waxy, and waterproof covering reduces the evaporation of water from leaves– Leaves obtain CO2 for photosynthesis from the air through pores in the epidermis called stomata (singular, stoma)Stomata Fig. 7-2Cells “swollen”Cells “flaccid”http://youtu.be/cFX4JrsPaUsLeaves and chloroplasts are adaptations for photosynthesis (continued)– Inside the leaf are layers of cells called the mesophyll– concentration of chloroplasts– photosynthesis occurs here– Bundle sheath cells surround the vascular bundles – form veins in the leaf – supply ????Leaf AnatomyLeaves and chloroplasts are adaptations for photosynthesis (continued)– Chloroplasts are organelles with a double membrane enclosing a fluid called the stroma – Embedded in the stroma are disk-shaped membranous sacs called thylakoids– The LIGHT DEPENDENT REACTIONS occur in and adjacent to the membranes of the thylakoids– The DARK REACTIONS (Calvin cycle) capture carbon dioxide and produce sugar occur in the stromaAnatomy of a Chloroplasttwo outer membraneselaborate inner membrane systemStroma: Thylakoid: one of the sacs within a chloroplast; chlorophyll is built into the thylakoid membranes; “penny-like” appearance Granum: a stack of thylakoids with a chroloplast; “stack of pennies” appearance Anatomy of a ChloroplastPhototropism–describes the process by which plants respond to the light in their environment –light-sensing hormone responsible for the curvature of plant shoots towards light is auxin –auxin collects primarily on the darker side of the stem and stimulates cell elongation –cells on the side not directly exposed to light will grow much faster than the opposing side, and the stem will curve towards the light source –growth away from light is called negative phototropismPhototrophismWhen sunlight is directly overhead, the auxin molecules are distributed evenly. Cells grow evenly.When sunlight shines on the plant at an angle, the auxin molecules move to the far (dark) side of the stem, causing those cells to elongate. Cell elongation results in the bending of the shoot towards light.Phototropism in Tomatoes - TimelapseExperimental timelapse video of tomato plants. This was taken over a period of several hours, one frame was taken every 6 seconds.http://youtu.be/Ze8NV7cvW8khttp://youtu.be/IIsvRwNRoVwPhotosynthesis consists of the light reactions and the Calvin cycle– Starting with carbon dioxide and water, photosynthesis converts sunlight energy into chemical energy stored in bonds of glucose and releases oxygen 6 CO2 + 6 H2O + light energy C6H12O6 + 6 O2carbon water sunlight glucose oxygendioxide (sugar)An Overview of the Relationship Between the Light Reactions and the Calvin Cycle Fig. 7-3Photosynthesis consists of the light reactions and the Calvin cycle (continued)– The “photo” part of photosynthesis refers to the capture of sunlight in the thylakoids – The “synthesis” part of photosynthesis refers to the Calvin cycle (DARK REACTIONS), which makes sugar from the energy captured in ATP and NADPH in the light reactionsAuthor Animation: Reactions
View Full Document
Unlocking...