Factors that effect on Photosynthesis

• Factors affecting photosynthesis:

  • In order to photosynthesise a plant needs light, water and carbon dioxide.
  • The availability of light and carbon dioxide can affect how much and how quickly (the rate) photosynthesis occurs.
  • Water is not considered a limiting factor as there is usually enough water for photosynthesis.
  • The other major environmental factor that affects the rate of photosynthesis is temperature.
  • Chlorophyll can also be a limiting factor - disease or environmental stress (like lack of nutrients) can affect the amount of chlorophyll present in a plant.
• Temperature (part 1):

  • The temperature of the environment affects how much kinetic energy all particles have – so temperature affects the speed at which carbon dioxide and water move through a plant.
  • The lower the temperature, the less kinetic energy particles have, resulting in fewer successful collisions occurring over a period of time.
• Temperature (part 2):

  • Increasing temperature increases the kinetic energy of particles, increasing the likelihood of collisions between reactants and enzymes which results in the formation of products.
  • At very high temperatures, however, enzymes that control the processes of photosynthesis can be denatured (where the active site changes shape and is no longer complementary to its substrate) – this reduces the overall rate.
• Graph showing the effect of temperature on the rate of photosynthesis:

  
• Light:

  • The intensity of the light available to the plant will depend on the amount of energy that it has to carry out photosynthesis.
  • The more light a plant receives, the faster the rate of photosynthesis.
  • This trend will continue until some other factor required for photosynthesis prevents the rate from increasing further because it is now in short supply.
• Graph showing the effect of light intensity on the rate of photosynthesis:

  
• Carbon dioxide concentration:

  • Carbon dioxide is one of the raw materials required for photosynthesis.
  • This means the more carbon dioxide that is present, the faster the reaction can occur.
  • This trend will continue until some other factor required for photosynthesis prevents the rate from increasing further because it is now in short supply.

   
• A graph showing the effect of the concentration of carbon dioxide on the rate of photosynthesis: