5.2 Factors Affecting Membrane Structure

Question 1

How does an increase in temperature affect membrane structure? (3 marks)

Answer 1

Phospholipids have more kinetic energy, so they move more, and the membrane is more fluid.
It loses structure.
The channel and carrier proteins denature.
Increased permeability of membrane.

Question 2

Describe how solvents affect membrane structure. (1 mark)

Answer 2

Organic solvents dissolve membranes.

Question 3

Why are alcohols used in wipes? (2 marks)

Answer 3

The alcohol dissolves membranes of bacteria in a wound, killing them and reducing the risk of infection.

Question 4

Beetroot cells contain a bright red pigment, betalin. What happens when temperature increases? (3 marks)

Answer 4

Membranes are disrupted
The red pigment is released and the surrounding solution is coloured
The amount of pigment released into a solution is related to he disruption of the cell membranes.