• 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

    Investigating Factors Affecting the Rate of Photosynthesis.

    5 star(s)

    I moved the lam 2Cm each minute and then counted the number of bubbles. As I moved the lamp away from the pondweed, the rate of photosynthesis limited, as shown in my graphs. The scientific knowledge is that plants need light to carry out photosynthesis and produce bubbles of gas,

  2. Marked by a teacher

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

    5 star(s)

    Original prediction The conclusions support a part of my predication. Review my predication, it said: "as the intensity of light increased, so would the rate of photosynthesis, the rate of photosynthesis will increase at a constant rate". On my graph, I can see that as the intensity of light increased, so does the rate of photosynthesis.

  1. Marked by a teacher

    Factors That Affect the Rate of Photosynthesis

    3 star(s)

    Range of Measurements: The range of measurements that we will take for the length of time the oxygen being collected for will be one minute per distance when the plant has begun to photosynthesize at a constant speed. We will be taking a result for three times for accuracy.

  2. Investigate the factors, which affect photosynthesis.

    Prediction My prediction is that the more intense the light, or more the chlorophyll, water and carbon dioxide the faster the rate at which photosynthesis is carried out. In other words I think the greater the light intensity, water, chlorophyll or carbon dioxide the greater the rates of photosynthesis.

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

    Mean volume of oxygen released at 35oC = 34.27307692. Mean volume of oxygen released at 65oC = 4.929230769. 2. Difference between means = 29.34384615. 3. Standard deviation of the volume of oxygen released at 35oC squared, divided by number of pieces of data = (11.36500358)2 = 9.935638952 13 4.

  2. How temperature affects the rate of photosynthesis.

    I also predict that the bubbles produced at 30 oC would be the highest and at 70 oC will be the lowest. Method: 1. Collect all equipment required. 2. Prepare 4 equal lengths of elodea each 50mm each using a ruler and scissors.

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

    This therefore proves my theory that the amount of water lost is directly proportional to the surface area, and therefore number of stomata. As you can see, there are some anomalous results in my graph, causing the curved line to waver.

  2. The effects of organic effluent from the seweage on the biodiversty in a freshwater ...

    Near the sewage, in the middle of the stream and one site further away near the fresh water so that differences in biodiversty can be measured by looking at the changing effluent levels in the stream. 3. Another site at the end of the stream consisting of mostly fresh water (Raised pond)

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