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

How light affects the rate of photosynthesis

Extracts from this document...

Introduction

How light affects the rate of photosynthesis Aim To see how light affects the rate of photosynthesis Introduction Photosynthesis occurs only when light is present, and takes place in the chloroplasts of green plant cells. The definition of photosynthesis is 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 like this: (Light) 6CO2 + 6H2O C6H12O6 + 6O2 (In the presence of chlorophyll) Also the word equation can be expressed like this: Light CO2 + H2O Glucose + O2 Chlorophyll Plants need light to photosynthesis, and so that without light, the plant would die. The reason that light intensity does affect the rate of photosynthesis is because the light energy is absorbed by the chloroplasts and then the chlorophyll makes then energy for the plant to use. There for if the more light taken by the chloroplasts (to a certain limit depending on the plant) ...read more.

Middle

1 x measuring flask (filled with tap water) 1 x piece of pondweed (eklodea) 1 x stopwatch 1 x pen and paper (to record results) The method I use is as follows: 1. Pour water into the flask to about 3/4 of the total. 2. Place the light source 50cm away from the pond weed. 3. Measure this accurately by using the 100cm ruler. 4. Start the stop watch as you turn the light source on. 5. Count the amount of oxygen bubbles being released from the pond weed during the time period of 1 minute and record your results. 6. Move the light source 10 cm closer 7. Begin counting the amount of bubbles again through a time span of 1 minute and record your results 8. Move the light source 10 cm closer Begin counting the amount of bubbles again through a time span of 1 minute and record your results 9. ...read more.

Conclusion

Ways of improving this experiment are limited I could have made more results by moving the light source 5cm closer each minute of prolonging the minute to 2 minutes to get more precise and accurate readings. Another factor that may have caused inaccurate readings was the light already coming in through the classroom windows I suggest next time placing blinds over the windows preventing any foreign light affecting the experiment. I do believe this test was fair as the only factor I changed was the range of the light source. I kept the light source the same, the pond weed the same, the water the same and the ruler the same. From this investigation I have learnt that plants are more complex then I first imagined, before this investigation I never took into consideration the plants we see all around us each day where making their own food constantly from now on I will see plants in an entirely different prospect. Joseph Maher ...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

    This is a very small difference, therefore the results for 25 degrees is very reliable. For the temperature of 35oC the maximum difference between the results for the rate of oxygen released is 6.44mm3/min. This is a significant difference, therefore the results for 35 degrees is largely inaccurate.

  2. How temperature affects the rate of photosynthesis.

    Therefore no oxygen is allowed out of the leaf. Also no carbon dioxide will be allowed to enter the leaf and the reactions taking place in the Calvin cycle will cease or their rate will decrease. This affect of temperature in reducing the rate of photosynthesis can be considered while drawing conclusions during the experiment.

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

    the amount of light reaching the plant is moved away, which I demonstrated in my experiment. The results support my original prediction in the way that as the light intensity decreased, the rate of the bubbles also decreased. The results show a decline in the number of bubbles as the

  2. INVESTIGATING HOW TEMPERATURE AFFECTS THE

    The independent variable in my investigation will be the temperature, as this will be constantly getting higher each time. Thus the dependant variable will be the pigmentation released. All the other variables will be kept constant as otherwise it could affect the results.

  1. Absorption Spectrum of Chlorophyll.

    the spinach extract had been diluted 20-fold and the okra extract was not diluted. At the blue maximum of 430 nm, the spinach had an absorbance of 0.885 while that of the okra was 0.311.

  2. Find out how light affects the rate of photosynthesis.

    Now we know the distances we are going to use we can work out the light intensity for each distance, by using the formula- Light intensity =1/d2 6cm - Light intensity = 1/36 = 0.027 Lux 9cm - Light Intensity = 1/81 = 0.012 Lux 12cm - Light Intensity= 1/144

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