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

An experiment to see how light intensity affects the photosynthesis of a plant.

Extracts from this document...


An experiment to see how light intensity affects the photosynthesis of a plant. Introduction The aim of this experiment is to determine whether or not the intensity of light will affect the rate of photosynthesis in a plant. In order to do this, I will place pondweed in different light intensities, and observe the amount of oxygen that is given off. Hypothesis I predict that as the intensity of light increases, so will the rates of photosynthesis. Furthermore, if the light intensity increases the rate of photosynthesis will increase at a steady rate until a certain 'peak' is reached, and then the rate will no longer increase. Photosynthesis will only occur in the presence of light. It takes place in the chloroplasts of green plant cells. It can be defined as the production of simple sugars from carbon dioxide and water, which causes the release of sugar and oxygen. The chemical equation for this is the following: The reason that light intensity will affect the rate of photosynthesis is because as the light (energy) falls on the chloroplasts in the leaf, the chlorophyll traps the light, which will then make the energy from the light available for chemical reactions to take place in the plant. ...read more.


In this experiment I will carry out, I hope to close the blinds in the room and not have the lights on, so the exterior light is not affecting my results. Though the preliminary experiment will, however, show me whether light intensity has any effect or not at all. In this case it has had an effect, and this preliminary experiment supports my hypothesis that as the light intensity increases, as the lamp gets closer to the plant, the rate of photosynthesis, shown by the amount of bubbles produced, increases as well. The experiment also shows that in order to obtain more readings, I should have a shorter time interval for each measurement of oxygen bubbles. Analysis I drew my graph with a line of best-fit curve. I did this instead of a straight line because of the clear pattern of the points on the graph. My graph shows me that an increase in light intensity will certainly increase the rate of photosynthesis. Both my graphs and my results support my hypothesis fully. The prediction I made that, as the light intensity increases so will the rate of photosynthesis, was backed up with the results I obtained in this experiment. This is because photosynthesis will only occur in the presence of light. ...read more.


If I were to carry out the experiment again over a longer period of time, in order to obtain more readings, it would then be necessary to add sodium hydrogen carbonate to the water so the carbon dioxide concentration would be increased. In my result tables, one table had a higher rate of oxygen bubbles produced than the other, and this is due to the fact I used different pondweed the second time, so carbon dioxide levels would not have been the same. Due to the small volumes of oxygen produced, my experiment was perhaps not as accurate as it could have been though I still think it was accurate enough to justify and support my hypothesis. I could improve the experiment by simply increasing the time taken, so fewer errors are able to occur. I could not make this adjustment due to time constraints. To extend my investigation into rate of photosynthesis further, I could try investigating other limiting factors individually, as well as perhaps trying to link in some of the other limiting factors with my current experiment. Further investigation into the light factor could be exploring the effect on the rate of photosynthesis by different coloured lights, which could also lead to whether any other types of lights, like fluorescent lights, would also have a different effect on the rate. ...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. Marked by a teacher

    Investigate the relationship between wavelength of light and the rate of photosynthesis using pondweed.

    3 star(s)

    Then I shall measure out 25ml of water into a test tube and place in one of the test tubs, after that the specially cut Canadian pondweed will be placed in the test tube. I then proceed to place this in front of the ray box, which has not yet

  2. How Light Intensity Affects the Rate of Photosynthesis

    Although this probably did not influence it much, it will have thrown off my results a bit. There was also the chance of light pollution from other people's experiments. To solve this I would have to performed the experiment alone, in a completely dark room where the lamp was the

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

    How Carbon dioxide affects photosynthesis: As carbon dioxide concentration increases, the rate of photosynthesis increases. At high concentrations, the rate of photosynthesis begins to level out due to factors not related to carbon dioxide concentration. One reason might be that some of the enzymes of photosynthesis are working at their maximum rate.

  2. How temperature affects the rate of photosynthesis.

    A high light intensity will mean more energy available for the electrons to be excited, so both cyclic and non cyclic photophosphorylation will take place at a higher rate. An increase in the rate of cyclic photophosphorylation will mean more ATP will be transported to the dark stage to be used.

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

    The water bath needs to be plugged in to electronically keep the temperature accurate. Therefore we will need to be careful not to get water near the plug points, as their could be a risk of an electric shock. Key Variables During my experiment I will vary one factor, this factor will be temperature.

  2. Free essay

    Solar Desalination Plant

    * Chosen: Diaphragm pump, model E5PS2X119. * Operates on 1/16 hp motor. * Brine product is produced at 0.2 m3/hr. Maximum discharge capacity of this pump is 3.18m3/hr * The brine product is left to build up for the first eleven hours of the operational day, then pumped out during the last hour of operation in the day.


    Cuvettes I will use a curvette to put the solutions in; I will place 2cm in each curvette using a 2cm pipette so that each has the same volume and so it is far more reliable to compare the results.

  2. The aim of my investigation was to determine how limiting factors would affect the ...

    This is also the reason why water and assimilate transport proceeds without losses. The other two layers in the leaf are the protective layers on the top and bottom called the epidermis. The cells in the epidermis make a waxy substance which spreads out over the leaf called the cuticle.

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