4.2 - Factors that affect Photosynthesis

• How does chlorophyll affect the rate of photosynthesis?


  Chlorophyll absorbs light energy
• Artificially creating conditions required

  • Greenhouses - trap heat, stop pests from getting in
  • Pump in CO2
  • Fertilisers - gives nutrients
• Inverse Square Law 


  the intensity of light decreases proportionally to the square of the distance form its source.

  light 🐟 1/

  distance^2
• Environmental Factors affecting Photosynthesis

  • Temperature
  • Light Intensity
  • CO2 Concentration
  • chlorophyll concentration
• How does the rate of photosynthesis vary with temperature?

  Rate initially increases with temperature because particles have more energy and move faster, so react more frequently.

  Highest rear is at optimum temperature for the enzyme.

  At higher temperature, the rate decrea as bonds holding the enzyme together begin to break and do the enzyme changes shape. Rate then falls to zero as the enzymes denature.
• What is the role of chlorophyll?

  To absorb light energy for photosynthesis
• Why may plants produce insufficient chlorophyll?

  They lack the required nutrients

  They have a disease like Tobacco Mosaic Virus