• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

An investigation into how the amount of light affects the rate of photosynthesis

Extracts from this document...

Introduction

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 ...read more.

Middle

We did this because we were having trouble getting results and we decided this would increase are chance of getting results. Also instead of adding a spatula of sodium hydrogen carbonate we weighed it and put in 0.1g. We did this because it was a lot fairer as one spatula could vary from another. The boiling tube will be put in a beaker filled with water to keep the temperature constant. We will put a thermometer in the boiling tube to keep the temperature constant. We need to keep the temperature constant because heat affects photosynthesis by speeding up the cellular activity. But if you heat a plant up over 40oC photosynthesis will slow down and the plant will die. Our experiment is to see if the light intensity effects photosynthesis so we need to measure the light intensity to see how much it changed by. We measured the light intensity using a light sensor this went just by the boiling tube. A clamp, attached to a clamp stand, will hold up the light sensor. By doing this will mean I am conducting a fair experiment. Summary of preliminary and final experiments Preliminary experiment Final experiment Pond weed length(cm) ...read more.

Conclusion

intensity 16.9 14.2 9.4 4.8 3.5 2.1 Temp oC 21/21/21 22/22/21 20/20/21 21/20/21 22/23/23 23/22/22 Did it keep constant / / / / / / Graph Prelim Final Why straight line or curve? From looking at my results I can tell that the amount of oxygen given off is affected by the light intensity. The graph shows the amount of bubbles decrease the further away the lamp. As you move the lamp further away the light intensity decrease. Conclusion By looking at my graphs and result tables I have found out that my prediction was right. The closer the lamp is to the pondweed the faster it photosynthesis. Also sciences back my result up because if you look at the formula for photosynthesis. Sunlight 6CO2 + 6H2O ((((((((( C6H12O6 + 6O2 Carbon dioxide + water Chlorophyll Sugar + Oxygen If you increase CO2 or H2O or sunlight it will increase the rate of the reaction but this can only work if there's enough of the other to limiting factor. Also if you decrease anything this will slow down the reaction. But H2O is unlikely to be a limiting factor in are experiment as there is enough water because pondweed is an aquatic plant. ?? ?? ?? ?? ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Green Plants as Organisms section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Green Plants as Organisms essays

  1. How temperature affects the rate of photosynthesis.

    itself around the molecule, distorting it into forming the transition state, and so speeding up the reaction. This is referred to as the induced fit mechanism. So enzymes lower the activation energy by stabilising the transition state, and they do this by changing the reaction conditions within the active site of the enzyme.

  2. The investigation is aiming to look at transpiration.

    It enabled me to get a more accurate result than carrying out the experiment once. Carrying out the experiment will reduce the risk of getting anomalous result. for the experiment to be reliable all the results have to be consistent, and repeating the experiment twice helps to increase the chances of getting consistent result.

  1. Find out how the amount of light, that is light intensity, affects the rate ...

    Finally if temperature gets too high it will destroy the chlorophyll enzymes. The rate of photosynthesis is affected by the amount of light energy to perform photosynthesis. It can only do it as fast as the light energy is arriving.

  2. The aim of our investigation is to find out how the amount of light, ...

    This is the evidence I have obtained: Here is a diagram of the set-up of my experiment: Method: The variables involved are light intensity, temperature, carbon dioxide, environment and availability of water. The effect of each variable is that light intensity can change the way the Elodea is photosynthesising, it

  1. An Investigation into Species Diversity with distance along a Pingo.

    This was repeated along the profile of the pingo, and measurements taken at 0.5m intervals. 6. The results were plotted on graph paper to show a profile of the pingo. This was then used to divide the pingo up into an appropriate number of zones that will be representative of the landform as a whole.

  2. Absorption Spectrum of Chlorophyll.

    Table 2. Comparison of Absorbance Readings in Round and Square Cuvettes Wavelength Absorbance using round 1cm-cuvettes Absorbance using 1cm square cuvettes Ratio of absorbances Uncertainty in Ratio 550 0.273 0.233 1.17 0.04 600 0.272 0.239 1.14 0.03 650 0.359 0.302 1.19 0.03 682 0.564 0.492 1.15 0.03 Table 2 indicates

  1. Investigation on How the Amount of Light Affects Photosynthesis.

    Clearly, in a water plant, like the pondweed, as long as the plant is fully submerged in water at all times, this will not be a problem. > Temperature - Enzymes are used in the photosynthesis reactions of a plant.

  2. Investigating how the amount of oxygen given off by Pond weed changes when the ...

    Fair test: To make it a fair test I will: * I will do each of the wattage three times to allow for any outlying results * I will be careful to use the same amount of pond weed in each batch, this should be roughly 5cm.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work