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

Investigation in to the effect of temperature on a cell membrane.

Extracts from this document...


Lab Report 1) Title Investigation in to the effect of temperature on a cell membrane. 2) a) Hypothesis The change in temperature will have an effect on the cell membrane. b) Null Hypothesis The change in temperature will have no effect on the cell membrane c) Prediction The increase of temperature will have an effect on the cell membrane. I think the higher the temperature the more pigment will be released from the cell vacuole, showing that the cell membrane is damaged. I also think the pigment must stay inside the cell when it is healthy as it is water-soluble and therefore may only move through the membrane by facilitated diffusion. I know temperature does have an effect on many of the components that make up the cell membrane. Firstly the cell membrane has many proteins, many passing all the way through the membrane. I know that proteins are made up of amino acids held together by peptide bonds. Also to form the protein tertiary structure the proteins has other bonds such as hydrogen, disulphide and ionic. When the temperature rises these bonds break causing the proteins to denature. They will then create holes in the membrane allowing the pigment to diffuse at a faster speed. ...read more.


These results also show that there was a massive increase between 60� and 70� suggesting that something considerable happened between these temperatures. Also the fact that the temperature had no effect on the membrane till approximately 45� is also significant. I have also worked out the correlation coefficient of my graph and found it to be 0.8. This showing at quite strong positive correlation showing that my results follow a general trend. 7) Explanation These results can be explained. I think the reason that there was no change in the membrane till approximately 45� is because at this temperature there is no effect on the components of the cell. Then at 45� we see a slight increase in the amount pigment released and this steadily increases till about 65�. I think the reason for this increase is the beginning of the breakdown of the lipids, creating little holes in the membrane. Then at 65� we see a massive increase in the amount of pigment released. At this point I think it is the protein denaturing causing bigger holes in the membrane allowing the pigment to flow freely through the membrane. I also have to consider that somewhere the fluidity of the membrane would cause holes in the membrane but looking at my graph it is hard to say where this occurs. ...read more.


During the experiment I had my beetroot in an empty beaker. By leaving them in the open air the discs may have become dehydrated meaning when placed into the water the water will first have to enter the cell by osmosis because the water potential inside the cell may be lower than that of the surroundings, this must happen first before the pigments can start to diffuse out, so for some of the time the beetroot is immersed in the water it is re-hydrating. Of course this means the beetroot that was left out the longest will have been the most dehydrated, therefore it would not start to diffuse for a longer time. The modification I would have made then was keeping the beetroot immersed in water during the experiment. Then there was the limitation of keeping the water bath at a constant temperature with just a Bunsen burner and the use of cold water. I don't think this would have been a major limitation because as long as the temperature was keep within in a degree or two no major difference would be found, but if it was raised or lowered it could have stopped or started to effect the membrane when not wanted. But a good modification would be the use of an electronic water bath. Aimee Kelly Page 1 07/05/2007 ...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

    Investigating the effect of temperature on the movement of pigment through beetroot cell membranes.

    4 star(s)

    Prediction: Having seen the results of my preliminary experiment and having used a couple of textbooks that showed me details on the structure of a cell membrane, I have formed a prediction that should correlate with my final results. The tonoplast membrane and the plasma membrane enclosing the cell both

  2. Marked by a teacher

    effect of temperature on beetroot pigment through membrane

    3 star(s)

    To make a buffer: - Dissolve one packet of buffer substance in 250 cm3 of distilled water. - A 250 cm3 buffer solution at pH 7 will be made. It would be better to use isotonic salt or sugar solution, however using readily available distilled water is an acceptable alternative.

  1. Marked by a teacher

    An investigation to examine the effects of temperature on membrane stability in beetroot, by ...

    3 star(s)

    Different proteins are specific to certain molecules hence the cell membrane being selectively permeable. These transport proteins allow molecules to diffuse through the phospholipid bilayer; diffusion is the movement of molecules from a high concentration to a lower concentration down a concentration gradient.

  2. 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)

  1. Marked by a teacher

    The effect of temperature on the permeability of beetroot membrane

    3 star(s)

    So more pigment will be released, as a result as the temperature increase the percentage absorbance will also increase. A2: Plan a procedure * Using suitable equipment and apparatus, list the steps to be followed (there is no need to list apparatus unless unusable items are suggested)

  2. Permeability of Cell Membrane in Beetroot Cells

    My results back up my prediction as absorbency increased with temperature. The individual readings were as expected, the absorbency increased with temperature and duration of the experiment. However, the last readings after 12 minutes for 10?C and 80?C showed to be anomalous as the absorbency decreased.

  1. Catalyse Investigation

    H2O (CM3) H2O2 % Time (min) Length (CM) No. Of bubbles 10 150 15 5 3 2 20 150 30 5 3 3 30 150 45 5 3 3 40 150 60 5 3 4 50 150 75 5 3 6 Average No.

  2. Spreadsheet report

    Creating the Graphs Before I began creating the graph since I was going to put it on a different sheet I renamed it and chose a suitable name for it. To create my graph I activated the cells I needed to create the graph and then clicked on the graph icon.

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