Cell Membranes

Question 1

Factors affecting membranes

Answer 1

Temperature- lipids have more kinetic energy so move faster making membrane more fluid like

Solvent- non-polar solvents like alcohols will insert into the bilayer and will push lipids out of orderly fashion which increases movement and permeability.

Question 2

Investigating membrane permeability

Answer 2

Using beetroot which have a red pigment called beta lines in the cell vacuole so pigments will leak out when the cell membrane is cooked.

High temperatures increase the permeability therefore causing the pigment to leak

The amount of pigment can be measured via a colorimeter.

Question 3

What is a colorimeter?

Answer 3

Passes light of a certain wavelength through a liquid sample and absorption levels are measured.
The more amount of light absorbed the greater the concentration of the solution

Filter in the colorimeter is used to select the colour of light, the light must be the opposite colour to the sample which is used