Photosynthesis occurs only in the presence of light, and takes place in the chloroplasts of green plant cells. Photosynthesis can be defined as the production of simple sugars from carbon dioxide and water causing the release of glucose and oxygen. The chemical equation for photosynthesis can be expressed as: (light) 6CO2 + 6H2O ( C6H12O6 + 6O2 (in the presence of chlorophyll)
The fact that all plants need light in order to photosynthesize has been proven many times in experiments, and so it is possible to say that without light, the plant would die.
The rate of photosynthesis and the amount of oxygen produced by a plant is affected by different factors such as light intensity, temperature, amount of water and amount of CO2. However in our experiment the main factors being tested that affect the rate of photosynthesis are light intensity, the amount of sodium hydrogen carbonate and the temperature.
How does light intensity alters and affects the rate of photosynthesis and the amount of oxygen produced in the plant weed?
I predict that as the intensity of light increases, so will the rate of photosynthesis and the amount of oxygen produced.
The reason that light intensity does affect the rate of photosynthesis is because as light, and therefore energy, falls on the chloroplasts in a leaf, it is trapped by the chlorophyll, which then makes the energy available for chemical reactions in the plant.
As the amount of sunlight, or in this case light from a bulb increases (because it is a computer simulated experiment), more energy is absorbed, so more energy is available for the chemical reactions, thus, more photosynthesis takes place in a given time and more oxygen and glucose is released.
If the light intensity of the bulb decreases, less photosynthesis takes place because less energy is absorbed by the plant and less energy is available for the chemical reactions, decreasing the amount of oxygen released.