Within the phospholipid bi-layer there are proteins, and these proteins are made up of polypeptide chains which are joined together by hydrogen, hydrophobic and peptide bonds. Once the temperature has increased above 40°C the molecules vibrate so energetically that these bonds break easily and therefore creating holes within the cell wall and phospholipid bi-layer, and allowing the beetroot pigment to leak out.
The biggest variation is found at the temperature 40°C. This is because the results below are steadily increasing and as soon as the temperature rises above 37°C the phospholipid bi-layer brakes allowing a lot of red pigment to leak out of the cell and so forth increasing the amount of pigment in the distilled water.
Within my data which I collected I have found one anomaly. The anomaly is taken from my second row of results (highlighted in red).
At the temperature 40°C, the first result I collected from this temperature was 0.75 arbitrary units and from the re-test results at the same temperature I got 0.41 arbitrary units. This is a difference of 0.34 arbitrary units.
This piece of data is not what I would have expected due to the first set of results, although the data at 55°C on the first and second tests are relatively the same.
Evaluation of Practical Work:
The anomaly which I have identified at 40°C is 0.41 arbitrary units this could be due to the size of the sample of beetroot used, if the sample was smaller than the other samples it was have less pigment which would suggested why the result is lower than expected. Another suggestion for why the result is lower than expected could be due to the loss of pigment in the preparation process, or from where the sample was taken from on the beetroot.
If the sample was taken from the centre of the beetroot the sample may have had more pigment contained within the cells, but if the sample was taken from closer to the surface of the beetroot it may not have had as much pigment within its cells.
All of the above instances could have affected the outcome of the results.
If any errors were to occur from the equipment the most likely would have been the temperatures of the thermostatic controlled water baths. The temperatures of these baths would not always have been constant and may have been slightly over or under the desired temperatures. This is because the heater on the water baths only start working once the temperature has dropped below what is required, once the heater has started working once again it causes the temperature to rise above what is required, then the bath once again cools to below the optimum temperature and the whole cycle starts once again.
Another inaccuracy which could have occurred was the size of the beetroot cubes, this would be due to the inaccuracy of the measuring equipment; this could explain the abnormality found within my results. If the cube was cut slightly smaller it would have reduced the surface area therefore decreasing the amount of pigment leaked from the sample.
Another reason for the anomaly appearing could be due to the preparation of the sample. Many of the cells could have been damaged causing pigment to leak out so reducing the amount of pigment leaked during the experiment.
A way of overcoming the inaccuracy of the measuring equipment is to have rulers which are graded more accurately which may help prevent inaccuracies occurring in the future.
The experiment should be repeated more than two or three times by doing so; it would be easier to work out a clear average between the results, see any trends and you would be able to see any anomalies more clearly.
