An investigation into how the amount of light affects the rate of photosynthesis
We are going to do an experiment on how the rate of photosynthesis is affected by the light intensity.
The plant that will be photosynthesising is called elodea. It is a pondweed therefore photosynthesises under water. We will now be able to count the oxygen bubbles or develop a method were we can collect the oxygen given off by the pondweed. Photosynthesis is what keeps a plant alive. The energy for photosynthesis to work comes from the sun the air and the ground. A substance called chlorophyll absorbs the sunlight. Chlorophyll is found in chloroplasts and chloroplasts are mostly found in cells in the palisade layer. Also for photosynthesis to be carried out it needs water and carbon dioxide. The carbon dioxide is dissolved into the water and the pondweed will get water and carbon dioxide through diffusion. The light is than used to make sugar out of carbon dioxide and water. The waste product is oxygen. Here is the equation
Sunlight
6CO2 + 6H2O ((((((((( C6H12O6 + 6O2
Carbon dioxide + water Chlorophyll Sugar + Oxygen
On are preliminary experiment we tried to measure the volume of oxygen produced but couldn't collect enough oxygen to measure, so instead we used a method where we counted the oxygen bubbles given off by the pondweed. The pondweed was put in a boiling tube and we started with the lamp 5cm away from the boiling tube and moved it back 5cm at a time until we got to 30cm. The boiling tube was filled with water so we could see the bubbles rise to the surface. We counted how many bubbles were produced in 1 minute and repeated this 3 times to get an average. We put 3cm of pondweed in the boiling tube and cut the pondweed at a diagonal angle (to increase the amount of water up take in the xylem) using a scalpel, on a white tile. The pondweed will be put in the boiling tube upside down. This is because the stomata are on the lower surface of the leaves. The stomata are were the oxygen escapes from the leaves. We will add a spatula of sodium hydrogen carbonate (NaH2CO3). This will increase the amount of carbon dioxide in the water meaning photosynthesis will be carried out faster. This makes sure we will get a result.
We are going to do an experiment on how the rate of photosynthesis is affected by the light intensity.
The plant that will be photosynthesising is called elodea. It is a pondweed therefore photosynthesises under water. We will now be able to count the oxygen bubbles or develop a method were we can collect the oxygen given off by the pondweed. Photosynthesis is what keeps a plant alive. The energy for photosynthesis to work comes from the sun the air and the ground. A substance called chlorophyll absorbs the sunlight. Chlorophyll is found in chloroplasts and chloroplasts are mostly found in cells in the palisade layer. Also for photosynthesis to be carried out it needs water and carbon dioxide. The carbon dioxide is dissolved into the water and the pondweed will get water and carbon dioxide through diffusion. The light is than used to make sugar out of carbon dioxide and water. The waste product is oxygen. Here is the equation
Sunlight
6CO2 + 6H2O ((((((((( C6H12O6 + 6O2
Carbon dioxide + water Chlorophyll Sugar + Oxygen
On are preliminary experiment we tried to measure the volume of oxygen produced but couldn't collect enough oxygen to measure, so instead we used a method where we counted the oxygen bubbles given off by the pondweed. The pondweed was put in a boiling tube and we started with the lamp 5cm away from the boiling tube and moved it back 5cm at a time until we got to 30cm. The boiling tube was filled with water so we could see the bubbles rise to the surface. We counted how many bubbles were produced in 1 minute and repeated this 3 times to get an average. We put 3cm of pondweed in the boiling tube and cut the pondweed at a diagonal angle (to increase the amount of water up take in the xylem) using a scalpel, on a white tile. The pondweed will be put in the boiling tube upside down. This is because the stomata are on the lower surface of the leaves. The stomata are were the oxygen escapes from the leaves. We will add a spatula of sodium hydrogen carbonate (NaH2CO3). This will increase the amount of carbon dioxide in the water meaning photosynthesis will be carried out faster. This makes sure we will get a result.
