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

A Basic Look at the Effect of temperature on the permeability of beetroot membrane

Extracts from this document...


A Basic Look at the Effect of temperature on the permeability of beetroot membrane Analysis The graph shows the colorimeter readings increase as the temperature increases, they increase by the most at higher temperatures. This is shown by a smooth curve. This means that the beetroot samples release more dye at higher temperatures. This is because higher temperatures cause the membrane structure to break down. The membrane structure: Membranes have two layers of molecules called phospolipids to make up their structure. Phospholipis consist of a glycerol molecule plus two molecules of fatty and a phosphate group, this looks like a head with two legs, their head is attracted to water, this means they're hydrophilic. The rest of the lipid (the fatty acid legs) is hydrophobic, which means they repel water. In aqueous solutions the phospolipids automatically arrange themselves into a double layer so that the hydrophobic legs are packed inside the membrane (away from the water) and the hydrophilic heads face outwards into the aqueous solutions. ...read more.


Enzymes are always denaturing, but at higher temperatures this occurs more rapidly. But at higher temperatures there are more collisions between the substrate and the active site so this would increase the reactivity, so a good balance must be found. The optimum temperature is about 43�C, this is called the optimum temperature. As the proteins start to break down, there is no longer a barrier to the cell The lipids in the bi-layer are slightly more stable than the proteins but 'melt' and breakdown at higher temperatures too. This in effect creates 'holes' in the membrane. Also the membrane is in part held together by the interaction of proteins and lipids with the cell's cytosceleton. These also fall apart as the temperature is raised making the membrane more permeable. This means that diffusion can take place easier. Diffusion Diffusion is the passing of molecules through a membrane, from a high concentration to a low concentration. In the experiment the beetroot dye (betalain pigments) ...read more.


Error Reduction/Relative Influence The Instructions should be improved by adding these points - Have everyone shake the tubes moderately for 10 seconds only at given times. - Make everyone wash the beetroot until the excess dye is completely washed off (at least for three minutes) - Everyone should vary the place in the beetroot they extract the cylinders from to be cut - The classes cylinders should all be cut by the teacher (or any other person) to ensure there is minimal variation between the thickness of the discs. Conclusion The experiment was successful as it clearly showed the effect of temperature on the beetroot membrane. It showed that the membrane becomes more permeable at higher temperatures, as was expected. This was explained by the fact that proteins denature with high temperatures and the phospholipids structure changes and becomes less stable, having devastating results on the membrane structure. Despite the limitations and errors, the results of the experiment were conclusive. (c)Hugh Howlett 2005 Written by Hugh Howlett, Cheltenham College, England. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Molecules & Cells 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 AS and A Level Molecules & Cells essays

  1. Marked by a teacher

    Beetroot Experiment. The purpose of this experiment is to determine the effect of temperature ...

    4 star(s)

    We need to ensure that the surface area for diffusion is the same. If different sized samples of beetroot are used, there is the potential that more pigment will diffuse out of the larger sample solely due to the surface contact with the water and not as a result of temperature alone.

  2. Marked by a teacher

    The Effect of Ethanol Concentration on the Permeability of Beetroot Cell Membranes to Betalain

    3 star(s)

    with 0% ethanol solution, place in colorimeter in exact position, put the cover on top and read the dial, record result to the nearest 1%, pour the liquid back in the boiling tube and clean and dry the tube thoroughly as other solutions may affect the following result.

  1. Marked by a teacher

    Effect of different temperatures on the permeability of beetroot cell membrane.

    3 star(s)

    Cholesterol determines how fluid the membrane is. It helps to control the fluidity, stopping it from becoming too fluid or too rigid, preventing the membrane from bursting. Cholesterol structure is very similar to a phospholipid, it too has a hydrophilic head and hydrophobic tale, which allows it to fit neatly in the phospholipids.

  2. Marked by a teacher

    The effect of temperature on the permeability of beetroot membrane

    3 star(s)

    At higher temperatures the cell membrane will be broken down more so there will be a greater release of the betalain pigment. * Predict the result of a test of the hypothesis to indicate the direction of the link As the temperature increases the phospholipid bilayer and the proteins which make up the cell membrane become damaged.

  1. Marked by a teacher


    3 star(s)

    Because the temperature has not gone beyond what the membrane is supposed to withstand, the permeability of the plasma membrane was not really affected at low temperatures (5�C to 35�C). But since the temperature has goes beyond limits that the membrane can withstand (temperatures from 35�C upward), then liquid solution (betalain pigment)

  2. Marked by a teacher

    effect of temperature on beetroot pigment through membrane

    3 star(s)

    The lower the temperature is associated with the higher percentage of light transmission, therefore, there is less pigment release at low temperature. As temperature increases, the percentage of light transmission decreases due to increasing pigment release. There are at least two possible explanations to why pigment is released: i)


    If the test tubes was shaken too much then more betalain pigment would have been further released however, this 7% error may have been as the result of the test tube not shaken well enough, resulting in very little emission of the betalain pigment.

  2. An experiment to test the effect of different temperatures on the permeability of cell ...

    -Now there are cylinders of beetroot with uniform diameter, they are of different lengths, and so their ends need to be cut using the scalpel, making each piece to be exactly 3cm long. -The pieces of beetroot could now be washed by placing all of them under cold running water

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