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

An investigation into the effect of light intensity on the rate of photosynthesis on a piece of elodea

Extracts from this document...


An investigation into the effect of light intensity on the rate of photosynthesis on a piece of elodea Plan: Method: 1) First I will put some water into a boiling tube and add 5 spatulas of Sodium Hydrogen Carbonate. I will add 5 spatulas of Sodium Hydrogen Carbonate as it reacts with water and forms carbon dioxide; also I have so much so that I have carbon dioxide in excess. 2) Then I will cut off 5cm of elodea and place it into the boiling tube. 3) Thirdly I will place the boiling tube in a test tube holder 5cm in front of the light source. 4) Then I will count the number of oxygen bubbles that rise to the top in 5 minutes. 5) I will repeat the experiment 2 more times, so I have a total of three results to work out my average as well as that it makes it a fair test 6) Also I will move the boiling tube 5cm away from the light source a total of 4 times. Equipment: Sodium Hydrogen Carbonate Spatula Boiling Tube Test Tube Rack Lamp Water Scissors Ruler Elodea Stopwatch Diagram: Prediction: I predict that as the distance from the light increases the average number of bubbles produced in 5 minutes will decrease. I think this because light plays a very important part in photosynthesis. Carbon Dioxide + Water Glucose + Oxygen As can be seen by the above equation light is the main source of energy for photosynthesis. ...read more.


This graph shows the effect of the temperature on the rate of photosynthesis Chloroplast is the most important organelle in plants for photosynthesis. It is found in mesophyll cells and it contains green chemical called chlorophyll which converts energy from the sun into chemical energy which is used in photosynthesis. The chlorophyll absorbs all white light apart from green, which it reflects as the chlorophyll is green. Light is very important for photosynthesis. It is the main supply of energy. The speed that light increases the rate of photosynthesis at, depends on the colour of the light from the spectrum. The rate of photosynthesis is at its best when there is red, orange or yellow light present. That is why in autumn the rate is very low because the leaves are a red, orange or yellow in colour, because the chlorophyll pigment has broken down leaving the more weaker chemicals like xanthophyll which reflect the red, orange and yellow instead of absorbing it. Also as photosynthesis is at its best in red, orange and yellow light it is very poor in green, as the chlorophyll is normally green in spring and summer, when light intensity is at its highest, therefore it reflects the light. As well as green light the rate of photosynthesis is poor in blue and purple light, but not as slow as green light. This is because the blue and purple are very close to the green light therefore it is not as good as red or orange light. ...read more.


As well as that I would have rinsed out the boiling tube a cleaned the spatula so that there is no contamination and that the pH of the water isn't affected. Furthermore I would get more than one person counting the number of bubbles that are produced and then take an average of what they get for each experiment or I would set up a computer so that it counts the number of bubbles that are produced, however that it a lot more complicated. As well at that if I do the experiment again I would check that the light is working properly and that it is shining as brightly as possible. Also next time I would do the experiment in a trough and have the light shining over the top so that it has only one medium to travel through and less light it lost due to reflection. An alternative experiment that I could use is to test the pH of the sodium hydrogen carbonate solution at the start and end of the experiment. For this experiment I would add 0.5 grams of sodium hydrogen carbonate into a trough of water. I would then stir the solution and take the pH by using litmus paper or universal indicator, it should be pH14 or thereabouts. I would then add the piece of elodea. I would then place the lamp so that it shines down on the plant limiting the amount of light that is reflected. After 20 minutes I would check the pH once again and the closer it is to pH7 the more it has been photosynthesising. ?? ?? ?? ?? Nilesh Mistry 11SD ...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. What is the effect on the rate of respiration of yeast cells with glucose ...

    These factors decreased the reliability of the results and consequently the reliability and accuracy of the deductions and calculations made during analysis. With this in mind, the graphs plotted and rates of reaction calculated were less reliable and accurate and so the conclusions drawn based on these values were in turn distorted, in other words they were less valid.

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

    This is called the activation energy. One of the main ways to give a activation energy is to heat it. Enzymes reduce the activation energy of the reactions they catalyse. They do this by holding the substrate or substrates in such a way that their molecules can react much more easily.

  1. Investigating the effect of Light Intensity on Elodea.

    Simplest method to use: I have decided to use the bubble counting method, as it is simple. It would be much more difficult to measure the volume of oxygen, to get data. Counting bubbles gives numerical data, volume of oxygen would perhaps be more accurate, but very hard to measure accurately.

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

    I will also measure the light intensity using a light intensity meter 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.

  1. How temperature affects the rate of photosynthesis.

    Also it would already be performing photosynthesis and therefore significant changes in results can be noted. * In the actual experiment, the elodea would be subjected to the lamp after it has been left to acclimatise in water and a different lighted source overnight.

  2. This experiment involves using a photosynthometer to investigate how temperature affects the rate of ...

    This would have allowed me to pin-point exactly the optimum temperature of the enzyme, which is involved in photolysis. Looking at the results above, there was an incidence where the temperature was not properly controlled (the ice investigation in which 3 bubbles were noted in the third minute).

  1. Investigation To Find The Effect Of Temperature On The Rate Of Photosynthesis Of Elodea.

    I am satisfied with the range of the results we covered but I do believe that the temperatures we measured could be more chosen with more reason instead of randomly picked in a given range. I would have also liked to have made more measurements to find the optimum temperature of the plant.

  2. Investigate the rate of photosynthesis in Elodea under different circumstances using pH as the ...

    into ATP, which is used as the 'fuel' of all living things. The chemical equation for photosynthesis is: Carbon Dioxide + Water + Light Energy --> Glucose and Oxygen 6CO2 + 12 H2O + light energy --> C6H12O6 + 6O2 +6H2O In the process of photosynthesis, several factors may affect

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