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

How light intensity affects the rate of photosynthesis.

Extracts from this document...

Introduction

How light intensity affects the rate of photosynthesis Introduction Photosynthesis occurs only in the presence of light, and takes place in the chloroplasts of green plant cells. Photosynthesis can be defined as the production of simple sugars from carbon dioxide and water causing the release of sugar and oxygen. The chemical equation for photosynthesis can be expressed as: chlorophyll 6CO + 6H O C H O + 6O light The fact that all plants need light in order to photosynthesise has been proven many times in experiments, and so it is possible to say that without light, the plant would die. The reason that light intensity does affect the rate of photosynthesis is because as light, and therefore energy, falls on the chloroplasts in a leaf, it is trapped by the chlorophyll, which then makes the energy available for chemical reactions in the plant. ...read more.

Middle

Predictions I predict that as the intensity of light increased, so would the rate of photosynthesis. Furthermore, I hypothesised that if the light intensity increases, the rate of photosynthesis will increase at a proportional rate until a certain level is reached, and the rate of increase will then go down. Eventually, a level will be reached where an increase in light intensity will have no further effect on the rate of photosynthesis, as there will be another limiting factor, in this case the level of carbon dioxide. Diagram Variables Table Variable Type Variable Name Value(s) Reason Input Light Intensity 10,20,30,40,50,60 cm away from test tube. This will provide a good range of results so I can come to a reliable conclusion. Output Amount of Oxygen produced. ...read more.

Conclusion

I.e. As light intensity increases, the amount of oxygen produced increases. If you double the light intensity, you would not double the rate of photosynthesis. My results show that my prediction was correct by showing that as the light intensity increases so does the rate of photosynthesis and once it reaches a certain level it then starts to decrease due to the limiting factor of carbon dioxide level. I know this because as I decreased the light intensity the amount of gas produced decreased. The light intensity is not directly proportional to the rate of photosynthesis because the light intensity doubled the rate didn't but it still did increase. The only anomaly was in experiment 3 for 30cm away. Therefore my experiment is reliable. ...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. Investigating the effect of temperature on the rate of photosynthesis

    A data logger will be a lot more accurate way of measuring fluctuations in temperature. A data logger is an electronic instrument that records measurements (temperature, relative humidity, light intensity, on/off, open/closed, voltage, pressure and events)

  2. How temperature affects the rate of photosynthesis.

    When the substrate molecule binds to the active site, temporary bonds are formed between the substrate and some of the enzyme's amino acids and a complex is formed. Structural changes occur so that the active site fits precisely around the substrate.

  1. Investigating the effect of Light Intensity on Elodea.

    * Carbon dioxide concentration could have affected the rate of photosynthesis. If there was too little sodium hydrogen carbonate added to the water, this would have limited the rate of photosynthesis. However, I do not think that the results of my experiment show this to be true, as there is no sudden levelling off.

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

    To shield my set-up from the effects of light from other sources, I would use a heat shield that will not affect my results. The heat shield shields the apparatus from HEAT. How are you going to shield it from ambient room lighting, so that only the lamp illuminates it?

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

    If light energy is limiting then the rate of photosynthesis slows down intensively. I moved the lamp 5 cm each minute and then counted the bubbles. As I moved the lamp away from the Elodea, the rate of photosynthesis limited.

  2. Investigate the effect of light intensity on the rate of photosynthesis in an aquatic ...

    It was from these results that I decided my smallest & greatest distances of the light source from the pond weed. Yet it was odd how the results were so similar, considering the distances were of 50cm apart. This contradicted my prediction, and it was from this I realized that

  1. INVESTIGATING HOW TEMPERATURE AFFECTS THE

    I will use a thermometer to measure the temperature and once the solution is heated I will once again use a pipette to transfer the water in to a measuring cylinder. I will start transferring the water slightly above the required temperature so that by the time I have transferred it all, it will have fell to the required temperature.

  2. How light intensity affects the rate of photosynthesis.

    They control the size of the stomata, enabling it to open and close, the plant needs to do this because although the stomata needs to open in order to take in carbon dioxide, the plant loses water through transpiration whilst the stomata is open and so the guard cells prevent the plant becoming flaccid and they prevent wilting and dehydration.

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