Cells: Investigating Cell Membrane Permeability Practical Flashcards
1
Q
What is the aim of this practical?
A
- The aim is to investigate how different variables (e.g temperature and solvent concentration) affect cell membrane permeability by doing experiments using beetroot
- Beetroot cells contain a coloured pigment that leaks out - the higher the permeability of the membrane, the more pigment leaks out of the cell
2
Q
Describe how to carry out this practical
A
- Use a scalpel to cut five equal sized pieces of beetroot. Rinse the pieces to remove any pigment released during cuttinf
- Add five pieces to five different test tubes, each containing 5cm3 of water
- Place each test tube in a water bath at a different temperature, for the same length of time
- Remove pieces of beetroot from tubes, leaving the coloured liquid
- Switch a colorimeter on and use blue filter
- Add distilled water to a cuvette and put in colorimter and calibrate machine to zero
- Transfer sample of liquid from first test tube to a clean cuvette
- Place in colorimter and record absorbance of solution
- Repeat with other solutions
- Analyse results - the higher the absorbance reading, the more pigment released, so the higher the permeability of membrane