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

This experiment involves using a photosynthometer to investigate how temperature affects the rate of photosynthesis in the elodea.

Extracts from this document...


Contents: Page 2 Abstract Page 3 Aim and Introduction Page 8 Prediction Page 9 Preliminary Investigation Page 12 Apparatus and Justification Page 13 Proposed Method Page 15 Analysis of Variables: Page 16 Reliability Page 17 Individual Results Page 18 Class Results Abstract: This experiment involves using a photosynthometer to investigate how temperature affects the rate of photosynthesis in the elodea. Using this apparatus makes it possible to measure the rate of oxygen production by the elodea specimen, while varying the temperature. Bubbles of oxygen molecules are collected in a capillary tube of the apparatus. When a suitable volume of gas has been collected in five minutes, it can be drawn (by a syringe) as bubbles along side the scale and the length of the bubbles measured. The volume of oxygen produced is calculated by multiplying the length of the bubble(s) by pie, which is then multiplied by 0.82 (radius of the tube). The results from this experiment have revealed that an increase in temperature correlates to an increase in the rate of photosynthesis up to 45o C. Beyond this temperature, the rate of photosynthesis starts to decrease in a non uniform manner. Aim: To investigate how temperature affects the rate of photosynthesis in the elodea specimen. Introduction: Photosynthesis is trapping or fixation of carbon dioxide followed by its reduction to carbohydrate (triose phosphate), using hydrogen from water. The necessary energy comes from the absorbed light energy. Light nCo2 + nH2O ======> (CH2O)n + O2 At high light intensities the rate of photosynthesis increases as the temperature is increased over a limited range. At low light intensities, increasing the temperature has a little effect in increasing the rate of photosynthesis1. Research has suggested that photochemical reactions (reactions dependant on light) are generally not affected by temperature. Having said this, research had also stressed that temperature can have a significant impact on the rate of photosynthesis. ...read more.


Ice b). Water maintained at 45o C c). Water at room temperature (tap water) Proposed Method: * Get hold of the elodea specimen and place it in the boiling tube. * Put the boiling tube in a beaker surrounded by ice. * Ensure the thermometer is standing upright in the beaker. * Note the initial temperature and maintain this throughout the experiment, either by means of adding or reducing the ice content. * Place the electric bench lamp towards the elodea specimen * Allow the elodea specimen to settle for five minutes or so. * On the fifth minute start timing for a further five minutes and count the amount of bubbles observed. Note: The same procedure must be carried out for the other two experiments, only altering the content outside the boiling tube. In order to keep the water temperature at 45o C, it is advised that cool water or some heated water (from the kettle) is added depending on the temperature observed. Prediction: I predict that when the elodea specimen is placed in ice, a few (one or two) oxygen bubbles will be observed, therefore photosynthesis will be limited. When the elodea specimen is placed in water at 45o C, more bubbles will be seen and hence the rate of photosynthesis will increase At room temperature, some bubbles will be seen but much less compared to the 45o C investigation, since the temperature is in between. Results: Ice: Time (minutes) Number of bubbles observed 1 1 2 1 3 3 4 0 5 0 Total: 5 Water maintained at 45o C: Time (minutes) Number of bubbles observed 1 3 2 10 3 12 4 3 5 1 Total: 29 Water at room temperature (tap water): Time (minutes) Number of bubbles observed 1 0 2 2 3 3 4 3 5 3 Total: 11 Discussion: From looking at my results, it appears to be that my prediction is reasonably accurate. ...read more.


The temperature can be maintained by means of adding or removing ice to the water baths. > Due to the limited number of water baths, there may well be the case of sharing a water bath to five others. This means five additional bench lamps would have an impact on my results (as light intensity increases rate of photosynthesis). The lamps may also contribute to the water baths getting hotter than required. Therefore it would be wise to carry out the investigation individually. > When the apparatus are set up, the syringe (on top of the capillary tube) must be pulled to draw the water into the capillary tube. This will remove any air bubbles initially present in the capillary tube and thus leaving no ambiguity. Results: Table: showing the results I obtained during the investigation Temperature (o C) Length of Oxygen bubble (mm) Volume of Oxygen (mm) Rate of photosynthesis (mm3/min) Average rate of photosynthesis (mm3/min) 0.00 1.00 2.01 0.40 0.67 0.00 2.00 4.02 0.80 0.00 2.00 4.02 0.80 10.00 4.00 8.04 1.60 1.87 10.00 6.00 12.06 2.41 10.00 4.00 8.04 1.60 15.00 8.00 16.08 3.22 2.68 15.00 6.00 12.06 2.41 15.00 6.00 12.06 2.41 20.00 8.50 17.09 3.42 3.02 20.00 8.00 16.08 3.22 20.00 6.00 12.06 2.41 25.00 9.00 18.09 3.62 3.49 25.00 9.00 18.09 3.62 25.00 8.00 16.08 3.22 30.00 8.00 16.04 3.21 4.02 30.00 10.00 20.11 4.02 30.00 12.00 24.13 4.83 35.00 12.00 24.13 4.83 5.23 35.00 14.00 28.14 5.63 35.00 13.00 26.13 5.23 40.00 4.50 4.50 1.81 1.81 40.00 5.00 5.00 2.01 40.00 4.00 4.00 1.61 45.00 3.00 6.03 1.21 1.41 45.00 4.00 8.04 1.61 45.00 3.50 7.04 1.41 50.00 2.00 4.02 0.80 0.87 50.00 2.50 5.03 1.01 50.00 2.00 4.02 0.80 55.00 3.00 6.03 1.21 1.07 55.00 3.00 6.03 1.21 55.00 2.00 4.02 0.80 60.00 0.50 1.01 0.20 0.33 60.00 1.00 2.01 0.40 60.00 1.00 2.01 0.40 65.00 1.00 2.01 0.40 0.27 65.00 1.00 2.01 0.40 65.00 0.00 0.00 0.00 Table: Showing the results obtained from the class ...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. Investigating the effect of Light Intensity on Elodea.

    * 1 Scalpel to cut the ends of the Elodea * 1 Stop clock to time the experiment * 1 white tile * 1 Spatula * 3x 1/4 Spatula of sodium hydrogen carbonate * 1m ruler Safety: * Keep the lamp and electricity plug + socket away from any water.

  2. Effects of temperature and carbon dioxide on photosynthetic rate in Elodea.

    The fall occurs at temperatures too low for it to be entirely accounted for the denaturation of enzymes. The effect of carbon dioxide on the rate of photosynthesis. In the light-limiting region the rate of photosynthesis is not affected by lowering the CO2 concentration.

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

    The rate of photosynthesis is limited by the factor in the shortest supply. The law of limiting factors states that when a physiological process depends on more than one essential factor being favourable, its rate at any given moment is limited by the factor at its least favourable value and by that factor alone.

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

    The pilot study showed that a range of 15?C to 30?C would be suitable to use. We needed at least five different variables to be able to obtain a suitable conclusion from the results. We also needed to get two replicates of the results to show any anomalous results and for averages.

  1. How temperature affects the rate of photosynthesis.

    The shape of the graphs and the results obtained made me realise that the rate of photosynthesis mainly depends on the functioning of enzymes. The graphs showed an increase in the average rate of oxygen production between 0 oC -45 oC (with peaks forming at approximately 42 oC i.e.

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

    ATP and reduced NADP are passed from the light-dependant to the light- independent reactions. The water in our experiment will be contained in the test tube the elodea is placed in, therefore it will be taken from here to be used in photosynthesis.

  1. Experiment to investigate the effect of different concentrations of Carbon Dioxide on the rate ...

    between experiments � a thermometer for measuring the solution temperature during each bubble count � a stopwatch for timing the bubble count � a scalpel for cutting a piece of Elodea � tile for cutting the Elodea on. Other requirements for the experiment: � A piece of Elodea � Stock

  2. An investigation in to the effect of temperature on the release of pigment from ...

    80) could possibly exceed the colorimeter readings due to the possible high intensity of light absorption. I will use a stop clock to time the 2 minutes. I will also use a colorimeter to carefull monitor the temperature of the water bath, making the required temperature ranges remain constant.

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