Crop Plants: Increasing Carbon Dioxide & Temperature (Edexcel IGCSE Biology (Modular))

Crop Plants: Increasing Carbon Dioxide & Temperature

• If a plant is given unlimited light, carbon dioxide and water and is at a warm temperature, the only thing limiting the rate at which it can photosynthesise is its own ability to absorb these materials and make them react

• However, most often plants do not have unlimited supplies of these things, so their rate of photosynthesis is limited by whatever factor is the lowest at that time (known as the limiting factor)

• There are three main factors that limit the rate of photosynthesis: 

  • Temperature 

  • Light intensity

  • Carbon dioxide concentration

Temperature

• As temperature increases the rate of photosynthesis increases as the reaction is controlled by enzymes

• However, as the reaction is controlled by enzymes, this trend only continues up to a certain temperature beyond which the enzymes begin to denature and the rate of reaction decreases

Light intensity

• 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

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