How cells acquire energy: Photosynthesis

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1. Overview of photosynthesis

• Give the overall equation of photosynthesis in terms of reactants and products
• Explain which of the starting materials for photosynthesis is the source of the oxygen we breathe
• Describe the structure and function of the different parts of the chloroplast: p 104
  • stroma
  • thylakoids

  Diagram the relationship between the light dependent and independent reactions See p 105

• 

2. Sunlight and energy

• Describe light in terms of its wavelength in nanometers
• Define photon, pigment, chlorophyll, accessory pigments
• Explain why plants are green in terms of light absorption and reflection

3. Light dependent reactions (Light reactions) p 106 - 109

• Explain the behavior of chlorophyll when it is exposed to light. Fig 7.8
• Explain the location and structure of photosystems in the chloroplast. Fig 7.9 and the function of the reaction center.
• Describe the main steps in the light reactions figs7.10 -7.11
• Explain the location and role of electron transport chains in the light reaction. See fig 7.12
• 
• Identify the role of the following substances in the light dependent reactions:
  • Water
  • Chlorophyll
  • NADP+
  • ADP
  • NADPH
  • ATP
  • Oxygen

4. Light-independent reactions (Calvin cycle p 111- 112)

• List the starting materials and their source
• Describe the main steps in the Calvin Benson cycle

• Identify the role of the following substances in the Calvin Benson cycle:
  • RuBP
  • PGA
  • ATP
  • NADPH
  • PGAL
  • Glucose

5. Special adaptations for photosynthesis

• Distinguish between C-3 and C-4 plants.
• Describe how many desert plants(CAM plants) conserve water and still carry out photosynthesis.
• Note C4 plants have adaptations that avoid exposure of the enzyme involved in carbon fixation to high oxygen concentrations.
• CAM plants conserve water by carrying out light dependent reactions during the day and light independent reactions at night.

6. Explain the environmental impact of photosynthesis.

• Explain the greenhouse effect
• Define global warming
• Explain how photosynthesis moderates the greenhouse effect
• Explain why deforestation also effects global warming.

7. Explain why the development of photosynthesis in cyanobacteria may have created a crisis for other life forms about 2.5 to 3.0 billion years ago.

Terms:

pgd 09/19/02 revised 09/21/05