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

An Investigate into the Effect of Light Intensity on The Rate of Photosynthesis

Extracts from this document...


An Investigate into the Effect of Light Intensity on The Rate of Photosynthesis Submitted by Simi Wang Aim The investigation aims to find the effect of light intensity on the rate of photosynthesis. Predication Before experiment, it is predicted that if the light intensity is increased the rate of photosynthesis will increase. Why? Chlorophyll Carbon Dioxide + Water Sugar + oxygen Sunlight Chlorophyll Sunlight Figure 1. Formula for Photosynthesis As shown in figure 1, in order for any plant to photosynthesis it needs three main raw materials: 1. Water 2. Carbon Dioxide 3. Light These are also known as 'limiting factors' of photosynthesis (another limiting factor that has not been mentioned above is temperature). Therefore, if the limiting factors are increased, the rate of photosynthesis should also increase. From figure 1, it can be concluded that photosynthesis couldn't happen without light. This is proven from a previous experiment, comparing a plant that has all the raw materials to photosynthesis, with a plant that has light limited. The result of this experiment was that when iodine solution, is added to the decolourised plant with all the right raw material to photosynthesis, it turned blue-black, which means glucose had been produced. And when iodine solution is added to the decolourised plant with limited light, it stayed reddish brown, which showed that glucose had not been produced. ...read more.


Do this twice and work out an average. Meanwhile, measure the temperature of the water after the acclimating time. 8. Repeat procedure 7 after placing the lamp at each of the following distances from the weed: * 15 cm * 25 cm * 35 cm * 45 cm In order to make this experiment safely the following must be kept strictly: * Do not fill the water to the top of the beaker to avoid spilling out on the floor, which might cause an accident when some one slips on it. * When blowing into the water, blow gently to avoid water being blown out of the beaker. * Place the wire of the lamp far away from any sink or water to avoid any electrical conduction, which would cause a serious accident. To make this experiment fairly, and the most accurate result could be obtained, the following key factors must be take into account: * The amount of water used must be the same in every experiment. * The same piece of weed must be used in each of the experiments. * The acclimatising time before each experiment undertaken must be the same. * When removing the lamp to different distance, it is essential to place the lamp as accurate as possible. ...read more.


The above causes could be limited by adopting the following methods: 1. To overcome the effect of unwanted light sources, the experiment needs to be done independently in a dark room. 2. To eliminate the heat effect from lamp, it is suggested that a column of water is fixed between lamp and test beaker shown in figure 5. Figure 5. A method of preventing temperature as a cause of the rate of photosynthesis. 3. To reduce the errors of counting the bubbles, the two measuring method below can be employed: * Stoke count - one stroke every 5 bubbles Or * Only count for 15 second and multiply the result by 4. 4. To avoid the effect of carbon dioxide concentration in the experimental results, fill beaker with water of the same concentration of CO2 in every experiment. In addition, the following measures should be helpful to make experiment more accurate: * Measure the volume of oxygen give off instead of counting the number of bubbles given off so it would be more accurate. Figure 6. Measuring the volume of oxygen. * Make multi-experiment at the same test condition. The further suggestion is given below for further extended experiment: 1. Using different wattage of bulb to change the intensity of light. 2. Using different colours of light to see which of the light in the spectrum is most effective at photosynthesis. 3. Increase the volume of carbon dioxide in the water to see if the rate of photosynthesis would change. ...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 Carbon Dioxide on the Rate of Photosynthesis

    The conclusion given can be re-enforced by the table of results that has been given, if the average number of bubbles for 0.2 grams is looked at then it can be seen that 98 bubbles are released but if the same recording is analysed for 0.6 grams then an average of 177 bubbles are produced.

  2. Experiment to Investigate the Effect of Temperature on the Rate of Photosynthesis in Elodea.

    GP is then reduced to triose phosphate in the presence of ATP and reduced NADP. ATP and reduced NADP are produced in the light dependant reaction. In high temperatures, to keep up with the high demand of ATP and reduced NADP, the light dependant reaction needs to take place quickly, relying on a lot of light.

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

    This occurs because molecules are moving more quickly and there is a greater chance of a collision resulting in a chemical reaction. At some point, a temperature is reached that is an optimum temperature. The photosynthetic reaction rate is at its quickest rate at this point.

  2. How temperature affects the rate of photosynthesis.

    This would be done by using different water baths set at different temperatures. Ice water will be used to obtain low temperatures if they cannot be achieved in a water bath. A thermometer will be used to ensure the temperature of the water bath stays constant and any changes will be made as necessary.

  1. An experiment to investigate the effect of Light intensity on the rate of photosynthesis.

    The ATP is the energy that fuels the reaction and this means that the light independent stage is totally dependent on the light dependant stage. This stage adds the hydrogen formed in the light dependant stage to the carbon dioxide taken in through the leaves.

  2. Experiment to investigate the effect of different concentrations of Carbon Dioxide on the rate ...

    the same distance of 5 cm, location and position every time because the same light intensity had to be delivered for each experiment, to minimise the number of variables � there will be no other light to ensure that the same light intensity is provided for each experiment � the

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

    I will check if heat is affecting the rate of photosynthesis because it could affect the temperature of the water and warm up the Elodea. I will measure the distance from the lamp and Elodea accurately, each minute the distance will be altered and 3 trys will be experimented on, to document my results reliably.

  2. Determine the effect of light intensity on the rate of photosynthesis in Eledeo.

    H2O --> 2H+ +2e- + 1/2O2 vi The light energy is trapped in the lamellae by the photosynthetic pigments called chlorophylls and carotenoides. Different pigments absorb different wavelengths of light. The photosynthetic pigments are arranged as photo systems. A photo system is a light-harvesting cluster.

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