Table of content
Research Question…………………………………………………………………..….2
Background information…………………………………………………………..…...2
Hypothesis………………………………………………………………………..……..5
Variables…………………………………………………………………………..…….6
Apparatus…………………………………………………………………………….…6
Diagram of apparatus………………………………………………………………….7
Safety apparatus..…………………………………………………………….………...7
Method…………………………………………………………………………………..7
Likely errors…………………………………………………………………………….8
Safety measures………………………………………………………………………....8
Predicted table of results……………………………………………………………….9

Research Question: How does light intensity affect the rate of photosynthesis?

Background Information:
Photosynthesis is a used by plants and other organisms, this process converts natural light energy, usually from the sun to chemical energy which can be then released to fuel that plant or other organisms. The organism absorbs the light energy, water, minerals and carbon dioxide in order to then produce glucose, which is like ‘food’ to the organism. Throughout this process oxygen is also produced by the plant, this oxygen is then released into the air making human beings able to breathe. Photosynthesis happens in the chloroplast of the plant, this process involves a formula which is:
6CO2 + 6H2O ------> C6H12O6 + 6O2
This formula represents the process of photosynthesis where:
CO2 = carbon dioxide
H2O = water
C6H12O6 = glucose
O2 = oxygen
The process of photosynthesis can be effected by 3 different elements, these are: sunlight, temperature and the CO2, O2 concentrations. As these 3 elements increase the product of photosynthesis will also increase and as these elements decrease the product produced by photosynthesis will decrease. Also as temperatures increase the rate rises and then falls as the enzymes denature.

Elodea is a water plant, where photosynthesis occurs. It lives in water and depends on light energy to convert chemical energy in order to grow and develop. Throughout this experiment it will be investigated how the light affects photosynthesis is Elodea.
Sunlight can affect photosynthesis because normally when there is more light the process of photosynthesis increase, this happens until the plan reaches the maximum photosynthesis point, which is then reached the plateau where the photosynthesis rate will be continuously resulting into after that point an increase in the light intensity won’t affect the process or the plant. As it is seen in Graph 1 as the light intensity increases the rate of photosynthesis also increase at a fast rate, until it reaches its plateau.

Temperature can also effect the process of photosynthesis. Usually at higher temperatures the process of photosynthesis is more effective than at cold temperatures, therefor as the temperature increases the more photosynthesis is produced. As the plant enzymes reach the optimum temperature, the rate of photosynthesis automatically increases. As the organism reaches its optimum temperature the rate of photosynthesis starts decreasing until the enzymes are denatured eventually stopping the rate of photosynthesis. It is visible in Graph 2 that as the temperature increases there is a gradual increase in the rate and as the optimum temperature is being reached there is a fast increase of rate until it reaches its optimum temperature where the enzymes denature, stopping the process of photosynthesis.

CO2, carbon dioxide a factor which affects the process of photosynthesis because as there is more CO2 in the environment the better the rate of photosynthesis will be. As the carbon dioxide concentration increases the rate of photosynthesis also increase until it is limited by another element. As carbon dioxide is usually in low concentrations in the atmosphere the increasing of CO2 causes a quick rise in the rate of the process of photosynthesis until it is reached its plateau, this happens when the rate of reaction