An Investigation into the Effect of Light Intensity on the Rate of Photosynthesis on a Piece of Elodea

An Investigation into the Effect of Light Intensity on the Rate of Photosynthesis on a Piece of Elodea

Plan:

Method:

1) First I will put some water into a boiling tube and add 5 spatulas

of Sodium Hydrogen Carbonate. I will add 5 spatulas of Sodium Hydrogen

Carbonate as it reacts with water and forms carbon dioxide; also I

have so much so that I have carbon dioxide in excess.

2) Then I will cut off 5cm of elodea and place it into the boiling

tube.

3) Thirdly I will place the boiling tube in a test tube holder 5cm in

front of the light source.

4) Then I will count the number of oxygen bubbles that rise to the top

in 5 minutes.

5) I will repeat the experiment 2 more times, so I have a total of

three results to work out my average as well as that it makes it a

fair test

6) Also I will move the boiling tube 5cm away from the light source a

total of 4 times.

Equipment:

Sodium Hydrogen Carbonate

Spatula

Boiling Tube

Test Tube Rack

Lamp

Water

Scissors

Ruler

Elodea

Stopwatch

Diagram:

Prediction:

I predict that as the distance from the light increases the average

number of bubbles produced in 5 minutes will decrease. I think this

because light plays a very important part in photosynthesis.

Light

Chlorophyll

[IMAGE]Carbon Dioxide + Water Glucose + Oxygen

As can be seen by the above equation light is the main source of

energy for photosynthesis. The energy it gained from the sun. The

chemical chlorophyll, which is present in the chloroplasts of the

mesophyll cells, absorbs the light and converts it into chemical

energy which can be used for photosynthesis. Light affects the rate of

photosynthesis depending on its intensity; the more light there is the

higher the rate. However it can get to a point where even though the