rate of photosynthesis: * Light intensity ..

I can now conclude that increase in light intensity does increase the rate of photosynthesis.

see if Light Intensity Affects the Rate of Photosynthesis

The content of phytochemicals is often induced by environmental factors, including light quality and intensity. For example, leaf camptothecin concentrations in display a significantly increase under blue light and 50% shading treatments (, ). Visible light had been reported to induce proanthocyanidin biosynthesis and affect their composition, whereas UV light specifically induced biosynthesis of flavonols (). In our previous studies, flavonoids production in plantations had been demonstrated to significantly positively correlate with total solar radiation (). In the present study, water-soluble polysaccharide content in leaves also followed the order L3 (1000 μmol m-2 s-1) > L2 (750 μmol m-2 s-1) > L1 (500 μmol m-2 s-1 - ). These results support the carbon/nutrient balance theory,, if light becomes limiting, the decline in photosynthesis may limit plant growth and accumulation of carbon-based phytochemicals ().

Aim: To see if raising the light intensity increases the rate of photosynthesis.

Light Intensity and the rate of photosynthesis - …


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.

Prediction:I predict that raising the light intensity will increase the rate of photosynthesis.

Farmers can use their knowledge of these limiting factors to increase crop growth in greenhouses. They may use artificial light so that photosynthesis can continue beyond daylight hours, or in a higher-than-normal light intensity. The use of paraffin lamps inside a greenhouse increases the rate of photosynthesis because the burning paraffin produces carbon dioxide, and heat too.

Graph: Shows the effect of light intensity on the process of photosynthesis in an aquatic plant.

The Effects of Light Intensity and Wavelength on the Rate of

As we can see, there is a close relationship between the action spectrum and absorption spectrum of photosynthesis. There are many different types of photosynthetic pigments which will absorb light best at different wavelengths. However the most abundant photosynthetic pigment in plants is chlorophyll and therefore the rate of photosynthesis will be the greatest at wavelengths of light best absorbed by chlorophyll (400nm-525nm corresponding to violet-blue light). Very little light is absorbed by chlorophyll at wavelengths of light between 525nm and 625 (green-yellow light) so the rate of photosynthesis will be the least within this range. However, there are other pigments that are able to absorb green-yellow light such as carotene. Even though these are present in small amounts they allow a low rate of photosynthesis to occur at wavelengths of light that chlorophyll cannot absorb.

BBC - Higher Bitesize Biology - Photosynthesis : …

My reason for believing this
is that as mentioned previously, light is one of the limiting factors
required for photosynthesis, and by lowering the amount of light
available to the plant, I will be decreasing the rate at which the
process of photosynthesis takes place in the plant.

carbon dioxide concentration and light intensity can all ..

Results were
Things to remember!
When there is no light, photosynthesis can't occur since light is the activation energy needed for plants to convert carbon dioxide and water to glucose and oxygen
When there is no light, the plants would use up oxygen therefore emitting carbon dioxide bubbles instead.
The plants should be given a couple minutes to start initiating the process of photosynthesis before you start timing.
The Scenario:
Reona and Michael have been growing aquatic plants for a while, specifically Elodeas which is a type of pond weed.

How Light Intensity Affects Photosynthetic Rate

You should see an upward curve/line present, if you are recording
light intensity on your graph, the reciprocal of the distance, other
wise stated as 1


This is perhaps the best choice of graph to construct, as it clearly
presents the idea that as the light intensity increases, so does the
rate at which oxygen is given off by the aquatic plant.