In the egg osmosis experiment we used a chicken egg as a model of an animal cell to demonstrate the movement of water across a semi-permeable membrane. We have learned about the different components of the plasma membrane, including the phospholipid bilayer, integral and peripheral proteins, glycoproteins and glycolipids. We know that it is sometimes referred to as a “fluid mosaic” referring to it’s flexible structure of different parts.
Today we are going to test the effect of temperature and solvents on the cell membrane, using cores of raw beetroot. Beetroot is brightly coloured due to the presence of betalain and this coloured pigment can assist us to determine the effect of different temperatures and concentrations of solvents on the cell membrane. When the cell membrane is damaged, the pigment leaks out, so the more damage that occurs, the darker the colour of the medium into which the pigment leaks.
Your task is to design and complete an experiment with an aim, hypothesis, list of materials and equipment, method, results, discussion and conclusion. Your variable can be temperature OR concentration of a solvent (ethanol, for example) or detergent.
Resources:
- Investigating the effect of temperature on plant cell membranes (from the Nuffield Foundation)
- An example of a practical report
- Another practical report
