Limiting Factors

• Limiting factor in photosynthesis

  Factor that limits the rate of photosynthesis
• Interpreting graphs to determine the limiting factor in photosynthesis

  1. Observe the rate of photosynthesis as different factors are changed

  2. Identify which factor causes the rate to increase when changed

  3. That factor is the limiting factor
• Factors that limit the rate of photosynthesis

  • Light intensity
  • Carbon dioxide concentration
  • Temperature
  • Amount of chlorophyll in leaves
• Light intensity is the limiting factor

  Rate of photosynthesis increases as light intensity increases
• Carbon dioxide concentration is the limiting factor

  Rate of photosynthesis increases as carbon dioxide concentration increases
• Temperature is the limiting factor


  Rate of photosynthesis increases as temperature increases
• Increasing temperature too much causes enzymes to denature and the rate of photosynthesis to fall
• Greenhouse


  Used by farmers to increase the rate of photosynthesis and crop yield
• How greenhouses are used to increase the rate of photosynthesis

  1. Provide extra light

  2. Provide extra heat

  3. Increase carbon dioxide concentration
• Using greenhouses to increase photosynthesis is expensive, so the increase in yield must justify the cost
• Oil burners can be used in greenhouses to release heat and carbon dioxide at the same time