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

Investigation into the rate at which beetroot dye diffuses through a cell membrane during a temperature controlled reaction.

Extracts from this document...

Introduction

March 2004 Investigation into the rate at which beetroot dye diffuses through a cell membrane during a temperature controlled reaction I am going to investigate the effect that water temperature has on the diffusion of anthocyanin through the cell membrane of a beetroot. I need to work out the optimum temperature for heating the beetroot so that the membrane does not break down and contaminate other parts of the salad. If the solution has a high concentration of anthocyanin it will be dark red and less light will pass through, this will be measured using a colorimeter. Temperature will be the independent variable, and the amount of red dye will be the dependent variable. I will conduct the experiment by increasing the temperature of the water surrounding the beetroot discs; I will use a range of different temperatures (20�C, 40�C, 60�C, 80�C and 100�C). In order to reach these temperatures I will use water baths that will be set up in the laboratory. However, the experiment being conducted at 20�C will take place at room temperature and at 100�C the beetroot will be heated in a beaker of boiling water on a tripod under a Bunsen burner. I plan to repeat the experiment three times in order to make sure that the readings are precise and reliable. The results will then be averaged so a graph can be plotted and accurate conclusions can be made. ...read more.

Middle

As above, the thermometer detects the temperature, the beetroot is added and the stop clock is timed for five minutes. * The results will be recorded in a table. * The experiment will continue until I have results for the range of water temperatures and an average will be taken. Before conducting the official practical assessment I carried out preliminary experiments to determine whether the initial measurements would provide precise and accurate results for analysis and thus achieve a beneficial conclusion. I investigated different volumes of water and varied the number of discs I used. I found that 10ml of water gave a volume suitable enough to allow sufficient diffusion of anthocyanin molecules but prohibit too much dilution of the intensity of the pigment concentration. The number of discs added to the water remained the same, yet the thickness was changed from 3mm to 5mm, as cutting was easier, increasing the likelihood of them being equal size. My prediction is that as the temperature increases so will the rate of reaction, thus releasing more dye. This is due to the kinetic theory which states as temperature increases, the kinetic energy of the substrate and enzyme molecules increases and so they move around faster and collide more often increasing the rate of reaction. However when the enzyme reaches its optimum temperature the rate of reaction will plateau as the membrane proteins are denatured. Results: - The table shows the percentage of light passing though the solution at different temperatures in all three experiments, and average has also been taken. ...read more.

Conclusion

This would have caused excess red pigment on the beetroot. I also didn't wash excess pigment off each disc and I cannot assess the amount of pigment that was left on each disc. The excess pigment can easily get into the water in the boiling tube and as a result cause a higher reading on the colorimeter. Devising a method to reduce the amount of excess pigment produced would make results more accurate and reliable. Also another reason for the anomalies could be the fact that the beetroot pieces were cut out of different parts of the beetroot. This could mean that different parts of the beetroot could have more red pigment than others, resulting in those beetroot discs with more red pigment diffusing out more red pigment when heated. Making sure each beetroot disc was cut out of the same place in the beetroot would cause all of the beetroot discs to hopefully contain the same amount of red pigment to start off with. If I were starting the experiment again I would conduct it on the same day so the beetroot would stay moist. I would also leave the beetroot discs in the solution for longer to allow a chance for further diffusion. If I were extend my investigation I would add a pH buffer, as this accompanies temperature in making the enzymes work at their optimum. I would also use a smaller range of temperatures, starting with 10 to about 50, as my results don't show a gradual break down of the membrane, it is more rapid. ...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 does temperature affect the permeability of a cell membrane in a beetroot.

    4 star(s)

    However at 45 ?C the proteins in the membranes denature causing the holes in the membrane to expand. This allows more pigment out. So between 50 and 60 ?C the membrane becomes more fluid with more gaps in the membrane allowing more pigment to escape.

  2. Marked by a teacher

    Core practical - Why does the colour leak out of cooked beetroot? Investigating the ...

    4 star(s)

    Measure 2cm3 of distilled water into a curvette and also measure 2cm3 of each solution of temperatures into separate curvette's.(be very careful not to mix up solutions). Adjust the colorimeter to read 0 for clear water and then take an absorbance reading for one beetroot solution and then set the colorimeter with the same clear water again.

  1. Peer reviewed

    Effect of Temperature on Beetroot Membrane Proteins

    4 star(s)

    filled with water at 20�C, although the temperature could move towards the actual temperature of the room. D Collection and Presentation of Raw Data Temperature/�C % Transmission 1 2 3 4 5 6 7 8 9 10 Average 3.5 90 99 98 90 88 97 94 94 93 96 93.9

  2. How Temperature Effects the Movement of Pigment Through Cell Membranes

    the beetroots leaked pigment, it was carried out using the same procedure described later but at a wider range of temperatures, the results are shown below: Temperature (�C) 20 30 40 50 60 70 80 90 Transmission (%) 99.00 99.00 98.00 98.00 93.00 50.00 27.00 9.00 Absorbency (%)

  1. Investigation into the diffusion of pigment from the cell membrane of Beetroot.

    I will change the temperature accurately by using the waterbath which has a thermostat and can keep water at the desired temperature. The range I aim to test is every 10? between 10?C and 80?C. This is a good range because it allows a wide range but can easily be achieved.

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

    If part of the cell's cytoplasm is disrupted (the proteins being denatured), it can possibly contribute to further release of the red pigment out of cells. This is because the red sap (pigment) will not be held together as well inside the cytoplasm as it otherwise will be if higher temperatures are not applied and the proteins are not affected.

  1. The factors affecting the rate of permeability in a cell membrane?

    The preliminary can also help decide how much water to use as too much water can dilute the colour of the beetroot too much and using too little water could leave too dark colour so the preliminary experiment should help decide how much water to use, I predict that 10cm� should be suitable amount.

  2. Experiment to determine the effect of temperature on the permeability of a cell membrane ...

    by the denaturing allows the pigment to flow out of the cell more freely. Therefore if the cell membrane became denatured the percentage of light absorbed would increase. If complete denaturing occurred to all the beetroot cells the percentage of light absorption would be the same for all the pieces

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