Permeability of Beetroot Cell Membranes
An experiment to investigate how temperature affects the
Permeability of beetroot cell membranes
Interpretation of Results:
From 0°C to 30°C there is a gradual increase of absorbency which shows
that as the temperature increases it is denaturing the cell wall and
cell membrane and allowing the beetroot pigment to leek out into the
As soon as the sample of beetroot is placed into the distilled water
diffusion occurs naturally, which is the net movement of molecules
from a region of high concentration (beetroot sample) to a region of
low concentration (distilled water).
From 40°C upwards there is a sudden increase of absorbency, this is
because the optimum temperature of which enzymes and cells can work at
is 37°C and as soon as you go above this temperature it will cause the
enzymes and cells to denature and cease from working as effectively.
Even if you then lower the temperature again the cell will not regain
its original shape.
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
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.