Photosynthesis Lab Report

Investigating Photosynthesis in Canadian Pondweed

Aim

The aim of the investigation is find out what factors affect the rate of photosynthesis. Photosynthesis should not occur if one of the limiting factors is not present.

Plan ====

The factors affecting photosynthesis are:

Light - This will affect photosynthesis because it is one of the limiting factors. Without light photosynthesis can't take place as it is the energy source.

Temperature - This will affect photosynthesis because plants will photosynthesise at a quicker rate at different temperatures. The plant will denature at about 40' C and kill the plant.

Carbon dioxide - This will affect the rate of photosynthesis

After the first test, which had no added sodium bicarbonate, I added 0.1 grams of sodium bicarbonate to each test up to 0.6 grams.

I will make sure it is a fair test by keeping the following the same for each test: I will use the same pondweed for each test. I will make sure the amount of sodium bicarbonate is measured to my best ability. I will leave the lamp the same distance away from the beaker of pondweed. I will keep the pondweed at the same temperature.

The things I will have to measure are the amount of sodium bicarbonate used for each test. I will also have to measure the temperature of the water which contains the pondweed otherwise it may affect my results because plants will photosynthesise at a quicker rate at different temperatures. I will also have to measure the distance of the lamp from the beaker. I will also have to time how long the pondweed is in the solution. I will make seven measurements from 0 to 0.6 grams of sodium bicarbonate doing each test twice.

For my experiment I will need the following equipment-

Pondweed, Beaker, Water, Lamp, Sodium bicarbonate, Glass rod, Scales and a stopwatch

Diagram

Carrying

We no that the plant was photosynthesising at a quicker rate because it was producing a lot of oxygen bubbles which is a waste product of photosynthesis. This helps to prove that my prediction was correct as I said the more carbon dioxide the plant was given the quicker the plant would photosynthesis, as carbon dioxide is one of the limiting factors of photosynthesis. Although I had 2 odd results my results are good enough to support my predictions. I had a curve of best fit but really I should have had a curve that levelled off at the end but instead it curves downwards this was probably due to the plant being poisoned because there was to much carbon dioxide present in the solution which made it denature.

Evaluation

Although I had 2 odd results my results are good enough to support my predictions. I had a curve of best fit but really I should have had