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

Investigate how light intensity affects the rate of photosynthesis using elodea (pondweed).

Extracts from this document...

Introduction

Aim: To investigate how light intensity affect rate of photosynthesis using elodea (pondweed). Planning: For this investigation when a pierce of elodea is illuminated 9light) by a lamp (electric) it produces small bubbles of oxygen gas as a result of photosynthesis. The number of bubbles produced per minute can be used as evidence or the measure of the rate of photosynthesis. Background information: Green plants need sunlight. They use the light energy to make a sugar called glucose. Glucose can be converted into another type of sugar called sucrose and carried to other parts of the plant in phloem vessels. Glucose can also be converted into starch and stored. Both starch and sucrose can be turned back into glucose and used in respiration. Photosynthesis happens in the mesophyll cells of leaves. There are two kinds of mesophyll cells - palisade mesophyll and spongy mesophyll. The mesophyll cells contain tiny bodies called chloroplasts, which contain a green chemical called chlorophyll. This chemical is used to catch the light energy needed in photosynthesis. This is the symbol and word equation photosynthesis: 6CO2+12H2O+energy=C6H12O6+6O2+6H2O. Factors affecting rate of photosynthesis: � Temperature � Carbon dioxide � Light intensity Effect of Temperature. ...read more.

Middle

I predict is that the closer the lamp to the pondweed the more bubbles there will be and the further away the lamp is from the pondweed the bubbles will increase. 2) I predict is that the rate of photosynthesis will increase when the lamp is closer and the rate of photosynthesis will decrease when the lamp is far away. 3) I predicted that at 10cm, I will count more bubbles than when it is at 30cm where I will count less bubbles. My predictions are based on previous year 10 elodea photosynthesis results. Fair Test To make this investigation fair I will make sure that I use the same pondweed. I will use same lamp. I will use the same number of watts. I will use the same amount of water and that I will use the same apparatus. If I do not keep these the same then investigation will not be fair and will not give me the right results. Safety: The safety I will use is I will wear gloves to protect my eyes, gloves to keep my hands clean and I will do my experiment standing up to secure my safety of dropping a chair. ...read more.

Conclusion

This meant that the rate of photosynthesis decreased as the light moved further away from the pondweed. This is because photosynthesis is a reaction, which needs energy from light to work, so as the amount of energy available from light increased with the rise in light intensity, so did the amount of oxygen produced as a product of photosynthesis. My graph shows that relationship between the light and the rate of the photosynthesis was a non-linear, as all the graphs produced had a curve. However as I expected in my hypothesis, it does not appear that the curve part on the graphs, the increase in rate is in fact proportional to the light. Evaluation and conclusion Overall my experiment went really well. There was nothing in this experiment, which I could not do. I kept it a fair test as I did not make any changes while I was doing it. I kept everything the same apart from doing the experiment on two different days I think if I had done It all in one day I would have got better result as where was a change over weather over the two days which I done the experiment this may be why I got some anomalous result. ...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. Experiment to Investigate the Effect of Temperature on the Rate of Photosynthesis in Elodea.

    Below are diagrams of an action and absorption spectrum. The action spectrum shows which wavelengths of light are most used in the process of photosynthesis. The absorption spectrum shows the wavelengths of light which are most absorbed by the plant.

  2. Investigating the effect of Light Intensity on Elodea.

    This method would perhaps take longer to do, if the lamp were to be positioned far away from the plant the rate of photosynthesis would be much slower. It would take a considerable amount of time for 20 bubbles to produced at a length of 60cm, but only a

  1. The aim of my experiment is to find out how light intensity affects the ...

    To make it reliable I used measurement meter ruler to measure the distance * Number of oxygen bubble given off - this is a result of the reaction pondweed takes in carbon dioxide (from the sodium hydrogen chloride) and Water to produce oxygen, this is noticed by the volume of

  2. How Light Intensity Affects the Rate of Photosynthesis

    only light source > Temperature - As said earlier, the higher the temperature of the water, the faster the rate of photosynthesis until it gets so hot that the plant gets denatured. The lamp produced a lot of heat which then could have raised the temperature of the water, influencing the results.

  1. To investigate the effect of light intensity on the rate of photosynthesis on elodea ...

    average of our results and therefore give us much more accurate results. I chose to time the number of bubbles given off for the first one minute. This is because in the first minute the bubbles were at their most effervescent and this enabled us to calculate how the light intensity effected the rate of photosynthesis.

  2. How does light intensity affect the rate of photosynthesis

    Therefore, for another improvement I would only do the reading for 2 minutes instead so the rate of photosynthesis stays level.

  1. Investigating the effect of temperature on the rate of photosynthesis

    This is an increase of 5.6mm3/min in a range of 15 degrees. Over the next 15 degrees, as the temperature increases from 15 degrees to 30 degrees, the volume of oxygen goes from 6mm3/min to 28.4mm3/min. This is an increase of 22.4mm3/min, which shows the volume of oxygen increases more rapidly as the temperature increases.

  2. How temperature affects the rate of photosynthesis.

    Then GP is reduced to two molecules of a three carbon sugar called triose phosphate (TP) by using the energy from ATP and the hydrogen atom from the reduced NADP, both received from the light dependant stages of photosynthesis. As ATP is used, ADP and Pi are released and as

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