Laboratory report on oxygen bubbling experiment to investigate of the effect of light intensity on the rate of photosynthesis
To investigate the effect of light intensity on the rate of photosynthesis.
Principle of design and Assumptions
It is known that light is required in the photochemical stage of photosynthesis. Nonetheless, it is uncertain that if rate of photosynthesis is related to light intensity.
Since oxygen is the produced from the photolysis of water in light dependent stage of photosynthesis, the amount of oxygen released per unit time reflects the rate of photosynthesis.
In the experiment, light intensity is varied by changing the distance of a ...view middle of the document...
Wait for 5 minutes and record the final readings in pipette. Calculate the rate of photosynthesis and take 2 more readings.
7. Repeat steps 2 to 5 using different distance between the plant and the bench lamp (0.2m, 0.3m).
8. Plot a graph with volume of gas collected per unit time against light intensity.
1. Cut surface of the plant should face upwards in the set up.
2. Check the thermometer at intervals of light intensity to ensure a constant temperature. Renew the water whenever there is change in temperature.
3. The lamp should not be placed too close to the plant to prevent the heating effect of light intensity.
4. The meniscus of the pipette should be read at horizontal level.
|Distance |Light |Rate of photosynthesis (cm3/min) |
|(m) |intensity | |
| |(1/distance2) | |
| | |Reading 1 |Reading 2 |Average |
|0.1 |100 |0.028 |0.019 |0.023 |
|0.2 |25 |0.018 |0.01 |0.014 |
|0.3 |11 |0.007 ...