An Experiment to Investigate the Effect of Light Intensity on the Rate of Photosynthesis

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An Experiment to Investigate the Effect of Light Intensity on the Rate of Photosynthesis

Introduction

Photosynthetic takes place in the chloroplasts of green plant cells;

it can produce simple sugars using carbon dioxide and water causing

the release of sugar and oxygen.

The chemical equation of photosynthesis is:

[IMAGE]6CO2 + 6H20 C6 H12 O6 + 6O2

it has been proven many times that plants need light to be able to

photosynthesize , so you can say that without light the plant would

neither photosynthesize or survive. The reason light intensity is

being used compared to whether or not a plant needs light. Is because

the experiment wants to show that the rates of photosynthesis will

vary according to how much light from a light bulb will be trapped in

the chloroplasts, in the leaf. The more energy trapped the more

efficient a chemical reaction can take place and the speed of

photosynthesis will increase. There are many things which can affect

the photosynthesis of a plant such as light intensity, temperature and

carbon dioxide levels. There will be a maximum level of photosynthesis

during the experiment it is called a limiting factor. This factor will

prevent the rate of photosynthesis from rising above a certain level,

even if the conditions are improved to meet the best requirements for

photosynthesis.

Variables

Input - Light intensityis to be varied by increasing and decreasing

the distance from the light source to the plant

Output - The rate of photosynthesisis to be measured by counting the

bubbles of oxygen produced by the plant every two minutes, and

therefore finding the rate of photosynthesis

Control - The amount of water available to the Elodea will stay the

same level in the 400 cm3 beaker. The colour of the lamp will stay the

same (yellow) as to plants Chlorophyll easily absorbs blue light,

however it does not easily absorb green or yellow light, rather it

reflects it, this decrease's the rate of photosynthesis. This can

easily be controlled, simply by using the same lamp throughout the

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