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

Investigate the factors that affect the rate of photosynthesis.

Extracts from this document...

Introduction

Introduction Photosynthesis is the chemical process, which takes place in every green plant to produce food in the form of glucose. Oxygen is also produced as waste. I am going to investigate the factors that affect the rate of photosynthesis. The factor I have chosen to investigate is light intensity. Does varying degrees of light intensity affect the rate of photosynthesis in a green plant. Canadian pondweed (Elodea) will be used for this experiment, as when placed in water it gives of bubbles of oxygen from the cut end. This factor makes it ideal for observing the amount of oxygen given off when placed under varied light intensities. Aim The aim of this experiment is to determine whether the intensity of light affects the rate of photosynthesis in plants. Background Knowledge Photosynthesis occurs only in the presence of light. It is a chemical process used to turn inorganic compounds, carbon dioxide and water into organic compounds, carbohydrates. Photosynthesis occurs in chloroplasts, which are tiny membrane-bound bodies containing the light-trapping pigment chlorophyll. The equation for photosynthesis is: Stephanie Ellis Aby Chlorophyll Carbon dioxide + Water > Sunlight > Glucose + Oxygen Chlorophyll 6CO2 + 6H2O > Sunlight > C6H12O6 + 6O2 There have been many experiments proving that all plants need light in order to photosynthesise. The reason that light intensity does effect the rate of photosynthesis is because as light falls on the chloroplasts in a ...read more.

Middle

Varying the distance the lamp is from the beaker changes the light intensity, this happens because, the further a beam of light travels, the wider the beam becomes, when the beam hits a surface the light is spread over the surface, but if the surface was closer the beam would not be as wide and therefore more intense. Next I cut the bottom of the stem of the Elodea and placed in to the water upside down. I left the Elodea for one minute before I started to time the amount of oxygen bubble in the three minutes. I did this because as I am using the same piece of Elodea for each experiment, therefore I can make sure that photosynthesis was not taking place. After the one minute, I started the stopwatch and counted the amount of oxygen bubbles released by the plant. I recorded my results on my result table. I then changed the water and repeated the experiment measuring the lamp 4cms away. Next I repeated the experiment with the lamp 6cms away, then 8cm away, and final 10cms away. When I looked at my results I notices an anomalous result for 6cms distance, therefore I repeated this distance. Results table Distance away from Elodea (cms) Frequency of oxygen bubbles (in 3 min period) ...read more.

Conclusion

The retest experiment produced 39 oxygen bubble following the pattern that I predicted, and the pattern other experiments. The anomalous result has been added in my graph. If I were to do this experiment again I would change my method using a measuring cylinder as described above. My experiment is more than adequate to use in schools, with limited equipment. But the amount of errors in my method was not reliable enough for top scientist to use. This is because of the high level of errors which where beyond my control. A top scientist would have the equipment need to produce an experiment to the highest degree of accuracy. To extend this investigation further I would change the variables for example the type of plant I was using. I would try different types of plant and see if the results are similar for each type of plant. Also I could investigate the rate of photosynthesis when I changed the in take of Carbon dioxide or change the temperature. If I was to change the variable of my experiment. Eg. Temperature. I would still more or less follow my method, only using a hot water bath and a thermometer to record the temperature and the number of oxygen bubbles produced. I would record the number of oxygen bubbles given off at 20oC, 30oC, 40oC, 50Oc and 60oC. If I decide to investigate this variable I predict that as the temperature increased the cells would be killed therefore decreasing the rate of photosynthesis. ...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)

    * I find it is quite difficult to draw a graph from these data, this is because when I calculate the distance into light intensity, they are not evenly distributed. If I use the data like this, the graph will not as the nice as that using evenly distributed numbers.

  2. Marked by a teacher

    Investigating Factors Affecting the Rate of Photosynthesis.

    5 star(s)

    In this experiment, I found out that light is needed in order for photosynthesis to take place. The middle part of the leaf was white while elsewhere turned blue/black. This was because there was no light supply in the middle of the leaf therefore photosynthesis did not take place as there was no starch produced.

  1. Marked by a teacher

    Factors That Affect the Rate of Photosynthesis

    3 star(s)

    (For example: For a distance of 5mm, we will begin taking results when the plant starts photosynthesizing, therefore it'll have bubbles coming out of the stem at constant speed. We will take this for one minute then take restart and repeat this procedure two more times).

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

    This is the enzyme rubisco's optimum temperature, meaning the temperature where the enzyme works at its maximum rate. This is where the enzymes have the maximum amount of kinetic energy, therefore the active site and substrate will collide more, with more energy forming the product GP at the fastest possible rate.

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

    In the medium surrounding the strands were motile, aerobic bacteria. After a few minutes, the bacteria had congregated around the portions of the filament illuminated by red and blue light. Assuming that the bacteria were congregating in regions where oxygen was being evolved in photosynthesis, Engelmann concluded that red and blue light are the most effective colours for photosynthesis.

  2. Three separate experiments which are to be carried out to investigate a plant's unique ...

    Hardly shrivelled at all. d) Very, very shrivelled. This is because the Vaseline stops the water from evaporating. We already know that water escapes most from the bottom, and so, when you stop it from escaping via the bottom (b), it makes much more of a difference than if you stop it escaping via the top (a).

  1. Investigate the factors, which affect photosynthesis.

    This means when the leaves change and adapt to their surrounding such as climate, etc. Evergreen plant has chlorophyll present in it. Chlorophyll is a green substance, which contains chloroplasts and makes the leaves green. Chlorophyll is important for photosynthesis. Magnesium is a green element, which is found in chlorophyll.

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

    There was enough evidence to draw a suitable conclusion. The equipment used was more reliable than counting bubbles but there were still inaccuracies in the experiment. Sometimes the air given off from the elodea, did not go into the funnel and is not recorded in the experiment.

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