The Effect of Temperature on the Permeability of Beetroot Membrane

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 theyÂ’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. The molecules are represented in the ‘fluid mosaic model’

shown below (the red bits are the legs of the phospolipids):

[draw diagram here]

If it was only made from phospolipids the membrane would be a barrier

to water, this is why there are other components scattered throughout

the phosphlipid by-layer.

Glycolipids are lipids which have combined with polysaccharides. These

may be involved with cell recognition but their exact role is not yet

known. They are found in the outer layer of cell membranes.

Glycoprotiens (seen in green on the diagram) are proteins with

polysaccharides atta...

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...root 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.