3.4 Factors Affecting the Rate of Photosynthesis Flashcards
What are the factors that affect the rate of photosynthesis? (4)
- Light intensity
- Temperature
- Carbon Dioxide
- Chlorophyll
What does the level of chlorophyll within an individual plant depend on? (3)
- Disease e.g. tobacco mosaic virus
- Environmental stress
- Lack of nutrients e.g. water
All these damage the chloroplasts, so they cant make as much chlorophyll
What happens if the temperature is too high when a plant is undergoing photosynthesis?
The enzymes it needs for photosynthesis and its other reactions will be denatured - the rate of reaction decreases dramatically
What do farmers use in colder temperatures when they want their plants to have a higher rate of photosynthesis? (2)
- Greenhouses, they trap the suns heat which increases the temperature
- Artificial heat: photosynthesis can continue in the night too
What will farmers do to ensure their plants have access to the right amount of carbon dioxide? (2)
- They will pump carbon dioxide into the greenhouse or use a
- Paraffin heater: releases heat and carbon dioxide as it burns
What are the benefits to greenhouses? (2)
- Trap the suns heat which increases the temperature, better for colder climates
- It’s enclosed meaning pests and pathogens cant get to the plants as easily
What will farmers use to ensure their plants have enough essential minerals?
Fertilisers
Describe and explain how the rate of photosynthesis varies with temperature
At first the rate of photosynthesis rises with temperature as the particles have more energy and move more quickly. This means they can react more quickly and so the rate is higher. However, as temperature rises above the optimum temperature for the enzymes involved, the enzymes may start to break down. This decreases the rate until it falls to zero, when the enzymes are denatured.
