Photosynthesis

• Plants

  Use light for their source of energy
• Photosynthesis


  The reaction that plants use to trap this light energy
• Photosynthesis


  • It is an endothermic reaction (takes in energy)
• Leaves


  • Contain the green chemical chlorophyll
  • Chlorophyll can absorb light energy
• Photosynthesis


  1. Plant takes in carbon dioxide and water

  2. Light energy is absorbed by chlorophyll

  3. Light energy is used to convert carbon dioxide and water into glucose

  4. Oxygen is also produced
• Light intensity is zero


  Rate of photosynthesis is zero
• Increasing light intensity

  Rate of photosynthesis increases
• Limiting factor


  When photosynthesis is not as fast as it could have been, because there was not enough of something (e.g. light, carbon dioxide)
• Increasing light intensity


  Rate of photosynthesis no longer increases
• Increasing light intensity

  Something else becomes the limiting factor (e.g. carbon dioxide level)
• Increasing carbon dioxide

  Rate of photosynthesis no longer increases
• Factors affecting rate of photosynthesis

  • Amount of chlorophyll in the leaf
  • Temperature
• Leaves with less chlorophyll


  Lower rate of photosynthesis
• Increasing temperature


  Enzymes work faster, rate of photosynthesis increases
• Continuing to increase temperature


  Enzymes denature, rate of photosynthesis falls