Factors that affect photosynthesis

• Factors affecting photosynthesis


  • Light intensity
  • Temperature
  • Concentration of carbon dioxide in the air
  • Amount of chlorophyll in plants
• Chlorophyll


  Pigment within chloroplasts that absorbs the light energy needed for photosynthesis
• Plants have less chlorophyll


  They won't be able to carry out as much photosynthesis
• Factors that can reduce chlorophyll levels in plants

  • Disease (e.g. tobacco mosaic virus)
  • Environmental stress
  • Lack of nutrients (e.g. water)
• Limiting factors for photosynthesis

  • Light
  • Carbon dioxide
  • Temperature
• Graphing factors affecting photosynthesis

  1. Plot light intensity on x-axis

  2. Plot rate of photosynthesis on y-axis

  3. As light intensity increases, rate of photosynthesis increases

  4. Rate plateaus when something else becomes limiting (e.g. carbon dioxide or temperature)

  5. Carbon dioxide graph - rate increases with concentration until plateauing

  6. Temperature graph - rate increases initially, then decreases as enzymes denature
• Graphs may show multiple limiting factors (e.g. light intensity at different temperatures)
• Graphs may show all three main limiting factors (light, carbon dioxide, temperature)
• How farmers can create optimal conditions for photosynthesis

  • Use greenhouses to trap heat and provide artificial light
  • Pump in carbon dioxide
  • Use paraffin heaters for heat and carbon dioxide
  • Use fertilizers for essential minerals
  • Use pesticides to control pests
• Creating optimal conditions for photosynthesis can be costly for farmers
• • The inverse square law states that the intensity of light decreases proportionally to the square of the distance from its source. L = 1/D^2