• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
Page
  1. 1
    1
  2. 2
    2
  3. 3
    3
  4. 4
    4
  5. 5
    5
  6. 6
    6
  7. 7
    7
  8. 8
    8
  9. 9
    9
  10. 10
    10

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

Extracts from this document...

Introduction

An investigation to determine the effect of light intensity on the rate of photosynthesis in Eledeo Introduction The process of photosynthesis is the transfer of light energy into chemical potential energy of organic molecules. An equation for photosynthesis is: i Photosynthesis is vital for existence of both plants and animals, as they are dependent on energy that is provided by the sun. 'Green plants and other photosynthetic organisms have the essential role of providing the entire input of energy to an ecosystem.'ii 'Photosynthesis in plants converts light energy to chemical energy in organic molecules. Animals eat plants, obtaining some of the chemical energy in the molecules they taken in.'iii iv In photosynthesis, there are two sets of reactions involved: -The light independent reaction (Calvin cycle), which take place in the chloroplast stroma. Its role is the fixation of carbon dioxide, which is reduced to carbohydrates, using hydrogen and water. The carbon dioxide combines with a pentose sugar to produce ribulose biphosphate (RuBP). This continues to form two molecules of a three-carbon molecule called glycerate-3-phosphate. From this, two triose molecules are created due to the presence of ATP and reduced NADP, of which some condenses to form hexose phosphates such as starch. The remainder regenerates RuBP. v I am going to concentrate on the light dependant stage of photosynthesis as I am going to investigate the effect of light intensity on the rate of photosynthesis. ...read more.

Middle

I will place my test tube with the pondweed into a beaker full of water and add cold water every time the temperature rises. To keep the surface area of the pondweed the same throughout the experiment, I will use the same pondweed, throughout the investigation. I will also allow 5 minutes for the pondweed to adjust to the environment and that is why I have timed my experiments for 15 minutes, to obtain accurate results. In an attempt to control the outside temperature, I will conduct my experiment in the dark, resulting in photosynthesis not occurring at the maximum rate. Apparatus Elodea Potometer Stopwatch Clamp Stand Beaker 15cm measuring cylinder Lamp Scalpel Thermometer Sodium Hydrogen carbonate Water Elodea is used as it enables us to see the bubbles being emitted as it is an aquatic plant. Sodium Hydrogen Carbonate stimulates photosynthesis if there are no obvious signs of bubbles being produced (this increases carbon dioxide availability). Apparatus to be set up as shown in diagram 1. Diagram 1 Safety Procedures - Potometer must be securely fixed to clamp. - Make sure that the apparatus are not close to the edge of the table - When conducting the experiment, do not sit down as the apparatus may fall on you - Do not consume any of the chemicals - Make sure that all bags and coats are put away tidily - All spillage's must be cleaned up ...read more.

Conclusion

There are no more electrons that can be excited and no further ATP can be synthesised. The light intensity of light on a given object from a constant source, in this case the spot light, is inversely proportional to the square of the distance between them so: Intensity = I/d2. By observing the results table and graph the optimum temperature, light intensity seems to be 0.01. Statistical analysis was done by using Pearson's product moment correlation co efficiency. The statistical test shows the strength of the relationship between the independent and dependant variable. By observing the graph, an anomalous result can be identified, as it does not fit on the line of best fit. This anomalous result may be due to fact that some of the oxygen that was meant to obtain dissolved into the water and the Elodeo stem not placed completely up the collecting tube so some of the oxygen was lost. The level of significance, which is 1% for the tailed hypothesis, has a value of 0.93437. The value obtained in this experiment was less than 0.93437. However 2.5% results will be due to chance as the value at 2.5% is 0.8783 and the value obtained in this experiment is greater than that. ix x i Cambridge Advanced Sciences Biology 2 Chapter 2 Page 17 ii Cambridge Advanced Sciences Biology 1 Chapter 7 Page 94 iii Cambridge Advanced Sciences Biology 1 Chapter 7 Page 93 iv Cambridge Advanced Sciences Biology 1 Chapter 7 Page 94 Figure 7. ...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

    An investigation into the effect of light intensity on the rate of photosynthesis of ...

    5 star(s)

    Though counting the number of the bubbles is not a very accurate way to get the rate of photosynthesis because the size and oxygen concentration varies of the bubbles, it still could show the rate of photosynthesis. Control variables These need to be kept constant because they will affect the

  2. Marked by a teacher

    An investigation into the effect of a germination inhibitor on the germination of seeds.

    3 star(s)

    Ignoring the presence of the inhibitor, there is another reason why some of the seeds in the Petri dishes germinated while others in the same dish did. This is because of competition between the seeds for water and light, known as intraspecific competition.

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

    Start with tap water, as the temperature of this would be nearest to 15oC. 3. Measure the temperature with a thermometer. If the temperature is a little higher than 15 degrees then we will add some ice cubes into the water tub to lower the temperature.

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

    P680 receives replacement electrons from the photolysis of water. ATP is synthesised as the electrons lose energy whilst passing along the carrier chain, as in cyclic photophosphorylation. Below is a diagram of the 'Z scheme' of electon flow in photophosphorylation: Light-independent stage - The fixation of carbon dioxide is a

  1. Water harvesting.

    And of course any more water the villagers catch can go for irrigation. Does this sound like an impossible task? Is there any village that does not have this land availability? India's total land area is over 300 million hectares.

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

    As light is needed for the reaction to take place, then the amount of light should affect the amount of oxygen left over. On the graph, the x-axis shows the light intensity at each of the distances and the y-axis shows the length of the oxygen bubble that was created at each of these different light intensities.

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

    Conclusion: From the results that I have gathered I can state that an increase in light intensity certainly does increase the rate of photosynthesis. As was also expected in my prediction, the relationship between light intensity and the rate of photosynthesis was non-linear.

  2. Investigating the effect of Light Intensity on Elodea.

    Fill a beaker with water (500cm3) of water and add a spatula of sodium hydrogen carbonate. Place a funnel and an upturned test tube full of water over the Elodea (as shown below): Measure a distance with a 1m rule e.g. 50cm from the plant and place the lamp there.

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