Rate of photosynthesis

Limiting factors in photosynthesis

• light intensity

• volume of carbon dioxide

• temperature

• (amount of chlorophyll)

Limiting factor

The factor which is stopping photosynthesis from happening any faster

Effect of light intensity

• Light provides the energy needed for photosynthesis

• Light intensity is directly proportional to the rate of photosynthesis

Effect of Light intensity on a graph

• As the light intensity increases the rate of reaction will increase and so there will be a straight line through origin

• The line begins to plateau at a certain point where the increase in light intensity no longer increases the rate of reaction

• light is no longer the limiting factor instead temperature or volume of carbon dioxide is preventing the reaction from being any faster

Effect of volume of carbon dioxide

• a raw material needed for photosynthesis

• Volume of carbon dioxide is directly proportional to the rate of reaction

Effect of volume of carbon dioxide present on a graph

• As the volume of carbon dioxide increases the rate of reaction will increase and so there will be a straight line through origin

• The line begins to plateau at a certain point where the increase in volume of carbon dioxide no longer increases the rate of reaction

• carbon dioxide is no longer the limiting factor instead temperature or light intensity is preventing the reaction from being any faster

Why isn’t water a limiting factor?

When water is a limiting factor of photosynthesis, this proves to be a more serious issue than the plant’s ability to photosynthesise efficiently as it can still respire

Effect of temperature

• enzymes are biological catalysts (made of proteins) that increase the speed of chemical reactions (e.g photosynthesis) in living organisms

• Enzymes are affected by temperature. If it exceeds the optimum then the enzyme becomes denatured (45*C). If it is under the optimum then they work slower = slower rate of reaction

• Temperature must remain optimum