To investigate the effects of the organic solvents (10% ethanol, 30% ethanol, 50% ethanol, chloroform and paraffin on the permeability of cell membrane of beetroot.

from the damaged cells as the resulting of cutting 4.

The discs were left inn a beaker if of water to avoid drying out,

5.

5cm3 of 10% ethanol, 30% ethanol, 50% ethanol, chloroform and paraffin and distilled water  were added separately into labeled test tubes. The control was set up using the distilled water 

6.

5 pieces of beetroot discs were added into each of the test tubes. Care must be taken to  prevent damage of the beetroot discs in transferring.

7.

The tubes were left for ___ minutes and were swirled occasionally with same strength to enable even distribution of anthocyanin in thee water.

8.

The discs from each test tube were removed carefully after ___ minutes. Care must be taken to prevent damaging the beetroot discs and leakage of anthocyanin into solution.

9.

The relative colour intensity of each tube was measured using a colorimeter in term of % light transmission in each solution. Light absorption% = 100 - %light transmission

Result: A table showing the effect of different solvents on the permeability of beetroot cell membrane Solution

Permeability of beetroot cell membrane = relative colour intensity of solution %light transmission (T)

light absorption% (100-T)

10% ethanol 20% ethanol 30% ethanol chloroform  paraffin oil water 

Discussion: 1. Interpretation of result Organic solvent chloroform and ethanol will dissolve phospholipids bilayer and destroy the membrane, so it becomes permeability to anthocyanin. The cell membrane of beetroot tissue will be destroyed by the organic solvents, thus releasing the red pigments in their cell saps. Beetroot tissue treated with organic solvents will give a more intense red colour than that treated with water. Ethanol dissolves the lipid component of the membrane and destroys the cell membrane. Membrane loses its selectively permeability. Red pigment leaks out. There will be increasing colour intensity in the solutions in which the beetroot tissue is treated with increasing concentration of alcohol.

2. Source of error  a)

The beetroot tissues might be damaged during handing, some pigment leaked out.

 b)

Beetroot discs were not blotted dry when transferred from paraffin oil / chloroform to the distilled water to allow time for outward diffustion.

c)

Beetroot discs were obtained by freehand sectioning and they might be of different size

d)

The amount of anthocyanin present in each test tubes might not be the same initially

e)

The cuvettes holding the red so1ution might be scratched and this would affect the measurement of % light absorption by the colorimeter.

3. Improvement of result a)

Handle the beetroot discs carefully so that anthocyanin would not leaked out accidentally

b)

Blot dry the discs before transferring the discs

4. Topic for further investigation

Conclusion: