Photosynthesis: Harvesting Light Energy by 7lwawD


									Photosynthesis: Harvesting Light Energy

Students should be able to:

   I. State the importance of photosynthesis and identify the plant structures that are
       involved in photosynthesis
           A. Conversion of light energy into the chemical bond energy
                     1. All organisms utilize chemical energy for their own needs
           B. The structure of a typical leaf
                            1. Significance of a flat thin leaf with regard to photosynthesis
                                   1. increase absorption of sunlight
                                   2. increase rate of transpiration (evaporation)
                            2. The role of stomates
                                   1. regulation of stomates with regard to CO2 and water
                            3. The role of the vein
                                   1. Transport of water to the leaf
                                   2. Support for the leaf
                                   3. Transport of the soluble products of photosynthesis
                                       to the rest of the plant
           C. The structure of the Chloroplast
                            1. thylakoid disks (grana) - site of the light reaction
                            2. Stroma- - site of the Calvin Cycle
           D. Absorption of light energy by pigments
                     1. Absorption spectrum of chlorophyll
                     2. Action spectrum of photosynthesis
                                   1. Englemann’s experiment with spirogyra
   II. Identify the steps by which light energy is converted to chemical energy during
       the light reactions.
           A. Absorption of light by the photo-systems
           B. Movement of electrons to carrier molecules
           C. The splitting of water into oxygen and protons
           D. The production of ATP due to the diffusion gradient across the thylakoid
                     1. Proton movement through ATP synthetase provides the energy to
                         “charge” ATPs
           E. The transfer of protons to NADP to form NADPH

   III. Discuss the importance of the Calvin cycle
           A. The “fixation” of carbon dioxide by Rubisco into the formation of 2PGA
           B. The use of ATP and NADPH to convert PGA into PGAL
           C. For every 3 times the Calvin cycle occurs 1 extra PGAL is generated
           D. The uses of PGAL
                     1. Regeneration of ribulose bi-phosphate
                     2. Provide energy to a cell by entering into cellular respiration
                     3. Production of other carbohydrates, amino acids, proteins, etc.
IV. Describe how environmental factors affect the rate of photosynthesis
       A. Carbon dioxide
       B. Light intensity
       C. Temperature
       D. Oxygen
                1. Photorespiration is counter-productive to photosynthesis

V. Describe adaptationd that combat water loss
      A. C4 plants
          1. Leaf structure
          2. alternative pathway to fix CO2
                  a. occurs with in mesophyll cells (no rubisco, no photorespiration)
                  b. photosynthesis occurs within bundle sheath cells
          3. CAM plants – open stomates at night

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