Rate of Photosynthesis

• Limiting factors are those which prevent photosynthesis from happening any faster
• 3 limiting factors of photosynthesis:

  • light intensity
  • temperature
  • concentration of CO2 in the air
• At night, light is the limiting factor of photosynthesis
• In winter, temperature is the limiting factor of photosynthesis
• if it's warm and bright enough, the amount of CO2 in the air is the limiting factor of photosynthesis
• Chlorophyll can also be a limiting factor of photosynthesis as it affects how much light is absorbed and therefore the rate of photosynthesis
• The amount of chlorophyll in a plant can be affected by disease or environmental stress, such as a lack of nutrients
• As the light level is raised, the rate of photosynthesis increases steadily, but only up to a certain point
• Beyond a certain point, as light level increases, the rate of photosynthesis will no longer increase because either the temperature or the CO2 level is now the limiting factor, not light
• the amount of carbon dioxide will only increase the rate of photosynthesis up to a certain point, where light or temperature becomes the limiting factor, not the carbon dioxide
• temperature affects the rate of photosynthesis as it affects the enzymes involved
• usually if the temperature is the limiting factor, it's because it is too low - the enzymes needed for photosynthesis work more slowly at low temperatures
• If the plant gets too hot, the enzymes needed for photosynthesis and its other reactions will be damaged - happens at around 45 degrees celsius