• 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

The aim of my experiment is to find out how light intensity affects the rate of photosynthesis in elodea (pondweed).

Extracts from this document...

Introduction

SCIENCE COURSEWORK PHOTOSYNTHESIS Aim: The aim of my experiment is to find out how light intensity affects the rate of photosynthesis in elodea (pondweed). To do this I will place the light intensity to various distances and observe the amount of oxygen bubble given off from the reaction Prediction: I predict that as the light intensity changes the rate of photosynthesis will increases of decreases dependent on the amount of light intensity. This will be observed by counting the amount of oxygen bubble given off from the reaction. The oxygen bubbles are given off as a waste product of the plant. Hypothesis: I hypothesised that if the light intensity increases, the rate of photosynthesis will also increase until a certain level is reached. After, the rate of reaction will than fall down, ultimately increase in light intensity will no longer affect the rate of reaction. This is because other factors effecting rate of reaction will be limited for example: carbon dioxide and temperature. Preliminary work To check if the range that I chose for my experiment were correct I carried out a preliminary investigation in which I counted the amount of oxygen bubble given off from the reaction at several distances in a given time. To adjust different light intensity I used a lamp at various distances from the reaction of the pondweed. I used the meter ruler to measure the various distances from the plant. Table of result (preliminary work) amount of sodium carbonate (g) ...read more.

Middle

Safety: * Wear goggles through out the experiment. * Do not touch the lamp as it might be hot. * Do not touch electrical equipment with wet hands. * Do not look into the lamp while on as it might effect the eye. Range: * 10cm * 20cm * 30cm * 40cm * 50cm How the collected data was made reliable: * I used a wide range of distances - 5 * Done the experiment 3 times so its reliable * Averaged out the 3 readings THE PROCESS OF PHOTOSYNTHESIS: Photosynthesis is the chemical process change which happens in the leaves of green plants. It is the first step towards making food not just for plants, but ultimately for every animal on the planet as well. During this reaction, carbon dioxide and water are converted into glucose and oxygen. The reaction requires energy in the form of sunlight, and chlorophyll must also be present. The glucose produced in the photosynthesis reaction can be converted to sucrose and carried to other parts of the plant in phloem vessels. Glucose can also be converted into starch and stored (the starch can later be turned back into glucose and used in respiration). Oxygen is a 'waste' product of photosynthesis. Photosynthesis takes place primarily in plant leaves, and little to none occurs in stems, etc. The parts of a typical leaf include the upper and lower epidermis, the Mesophyll, the vascular bundle(s) (veins), and the stomata's. The upper and lower epidermal cells do not have chloroplasts, thus photosynthesis does not occur there. ...read more.

Conclusion

Evaluation In my opinion I think that this experiment was quite successful overall, since I followed the way I did my preliminary experiment as it was accurate enough to be the base of my final experiment. The method that I used was accurate enough to give me a reliable data however there were some error which affected my results such as the heat generated by the lamp. As I have earlier described, temperature has a very noticeable effect on the rate of photosynthesis, to stop this I used the screen in front of the lamp so the heat does affect the process of photosynthesis yet because the screen was quite small the heat escaped and affected the reaction. Another error was counting the bubbles; because I counted the bubbles visually I think it made the experiment unreliable therefore to make my experiment reliable and fair next time I would use a gas syringe to measure the volume of oxygen given out from the process of photosynthesis. I think that the result that I found was reliable overall because on my graph there was only one anomalous point which didn't fit the curve of best-fit this might have been because of one of the reasons from the errors which I mentioned earlier in the evaluation might have affected the result at that point Overall, I felt that due to the small volumes of oxygen involved, my experiment was not as accurate as it could have been, however I believe the result that I got from this experiment was accurate enough to support and justify my hypotheses and prediction. ...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

    How the molar concentration of NaHCO3 (Sodium Hydrogen Carbonate) affects the rate of photosynthesis ...

    5 star(s)

    In the following graph, it is clear that there is a general pattern that backs up this fact (that as the concentration of NaHCO3 is increased, the number of bubbles produced also increases). Using the table above, the existing relationship is clear with the only exception to the pattern occurring

  2. Marked by a teacher

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

    5 star(s)

    I am going to put a ruler between the desk lamp and the beaker. Every time I move the desk lamp, I would get a distance. From the distance, I could calculate the light intensity by this equation: I am going to take 5 distances and measure the oxygen bubble produced in each distance.

  1. Marked by a teacher

    Light Intensity and Photosynthesis.

    4 star(s)

    I also therefore needed a way of accurately measuring the light intensity, and I did this using a photometer. I recorded the lux reading (unit of light intensity) at each distance. I got the following results: Results of preliminary experiment Distance Light intensity No.

  2. Marked by a teacher

    Investigation to find out how light intensity effects the rate of photosynthesis

    4 star(s)

    Artificial light is used in glasshouses when extra light is needed. In water, only the top few meters get sufficient light for plants to use in photosynthesis. Plants that are able to detect a source of light grow towards it, for example, cress.

  1. How Light Intensity Affects the Rate of Photosynthesis

    -Temperature - In a plant, enzymes are used to control photosynthesis reactions in a plant. Therefore if the temperature of the water increases, the rate of photosynthesis will increase until the pondweed becomes denatured. I am maintaining a rough constant temperature for all the tests as each time the water is coming from the taps at around room temperature.

  2. Investigate the effect of light intensity and the colour of light on the rate ...

    Result table: Colour Distance (cm) Number of bubbles Average Temp White 10 390 330, 320 325 15 20 114, 190, 132 138 15 30 46, 41, 49 45 15 40 18, 19, 16 18 16 50 10, 9, 12 10 17 Red 10 370, 300, 300 300 15 20 91,

  1. How light intensity affects Photosynthesis.

    I will use a water plant (Canadian pondweed) as these types of plants can easily survive in water and this will be necessary for my experiment. Otherwise any plant that could not survive in water would die and therefore not be suitable for my experiment.

  2. I am going to do an experiment about photosynthesis but before we do this ...

    The heat may affect the rate of photosynthesis; if you put it in a water bath the temperature will stay constant because it absorbs heat and the amount of pondweed we put in would affect the amount of bubbles produced.

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