4.1.2 Rate of Photosynthesis

• What 4 factors affect the rate of photosynthesis?

  Light intensity, carbon dioxide concentration, temperature and amount of chlorophyll.
• What is a limiting factor?


  A factor which prevents a reaction from going any faster.
• Which factor limits photosynthesis at night?


  Light intensity.
• Which factor often limits photosynthesis in winter?

  Temperature.
• Which factor often limits photosynthesis when it’s warm and bright?

  Carbon dioxide concentration.
• Why may a plant have less chlorophyll?

  Disease or environmental stress.
• How does carbon dioxide concentration affect the rate of photosynthesis?

  The rate of photosynthesis will increase with carbon dioxide concentration up to a point where another limiting factor comes into place.
• How does temperature affect the rate of photosynthesis?

  The rate of photosynthesis will increase with temperature until it reaches the optimum temperature. After this point, enzymes used in photosynthesis will denature and so further temperature increase will lead to a decrease in the rate of photosynthesis.
• What temperature are enzymes normally destroyed at in photosynthesis?

  45°C.
• How does light intensity affect the rate of photosynthesis?

  The rate of photosynthesis will increase with light intensity up to a point where another limiting factor comes into place.
• Why does the rate of photosynthesis increase with light intensity?

  More energy becomes available.
• Why does the rate of photosynthesis increase with carbon dioxide concentration?

  More building blocks are formed.
• How do you calculate the rate of photosynthesis?

  Bubbles per minute.
• Where are limiting factors important?

  Greenhouses for the economics of condition enhancement to gain the maximum rate of photosynthesis while still maintaining profit.