Stomata and Transpiration - Coggle Diagram
Stomata and Transpiration
Measuring using a petometer
The uptake of water can be measured using a potometer. Under normal circumstances, the rate of water uptake gives a measure of the rate of transpiration.
A simple potometer is a piece of capillary tubing to which a plant has been connected. The water uptake is measured by recording the time taken for a bubble in the tube to move a set distance.
Aim of the experiment
To find the rate of water uptake of a plant.
Transpiration is affected by environmental factors
Brighter the light the faster the rate of photosynthesis
If there is plenty of light, photosynthesis can take place
If there is little or no light photosynthesis will stop
Carbon Dioxide Concentration
Any one of the factors could be the limiting factor
In a science lab or greenhouse the levels of carbon dioxide can be increased artificially
The atmosphere is only about 0.04% carbon dioxide, so on a normal sunny day, carbon dioxide tends to be the limiting factor
This allows the plants to photosynthesize and grow much quicker
In a garden, field or woodland this is not the same
Light intensity, temperature and carbon dioxide concentration interact with each other in these places
Carbon dioxide concentration increases at night because plants respire during the night but don't photosynthesize
Photosynthesis is controlled by enzymes are most get denatured once the temperature rises to around 40-50 degrees Celsius
If the temperature gets too high, the enzymes denature and the rate of photosynthesis falls
As the temperature rises the rate of photosynthesis increases as the reaction speeds up