植物光合作用全英文课件photosynthesislecture.pptVIP

10 During photosynthesis, plants Take in oxygen, produce CO2, and produce carbohydrates Take in oxygen, produce CO2, and consume carbohydrates Take in CO2, produce O2, and produce carbohydrates Take in CO2, produce O2, and consume carbohydrates None of the above You are supposed to teach us this stuff! What Is Photosynthesis? Photosynthesis: “Synthesis from light” The broad outline: Plants take in CO2, produce carbohydrates, and release water and O2 Light is required The Ingredients for Photosynthesis What Is Photosynthesis? Two pathways: Light reactions: Convert light energy to chemical energy as ATP and NADPH Light-independent reactions: Use ATP and NADPH (from the light reactions) plus CO2 to produce carbohydrates An Overview of Photosynthesis Movie Time! How Does Photosynthesis Convert Light Energy into Chemical Energy? Light is a form of electromagnetic radiation. Light is propagated as waves—the energy of light is inversely proportional to its wavelength. Light also behaves as particles, called photons. Which wavelength of light has the most energy? Red Orange Yellow Chartreuse Green Blue Violet 10 The Electromagnetic Spectrum How Does Photosynthesis Convert Light Energy into Chemical Energy? When a photon meets a molecule it can be: Scattered—photon bounces off the molecule Transmitted—photon is passed through the molecule Absorbed—molecule acquires the energy of the photon. The molecule goes from ground state to excited state Figure 10.5 Exciting a Molecule (A) Figure 10.5 Exciting a Molecule (B) How Does Photosynthesis Convert Light Energy into Chemical Energy? Photons can have a wide range of wavelengths and energy levels. Molecules that absorb specific wavelengths in the visible range of the spectrum are called pigments. Absorption and Action Spectra How Does Photosynthesis Convert Light Energy into Chemical Energy? Several types of pigments absorb light energy used in photosynthesis: Chlorophylls a and b Accessory pigments: Absorb in red and blue regio