5.2 Factors affecting membrane structure

Question 1

How does alcohol affect the membrane structure

Answer 1

Dissolves membrane:
Alcohol molecules are non-polar enough to enter phospholipid bilayer
High concentrations of alcohol solution disrupts/dissolves membrane

Question 2

What effect do organic solvents have on the structure of the membrane

Answer 2

Dissolves membrane:
Most are less polar than water
Cannot interact with phospholipids to keep phosphate heads outwards & fatty acid tails inwards

Question 3

Why cant small polar molecules diffuse via simple diffusion through the phospholipid membrane

Answer 3

As the bilayer has a hydrophobic core

Question 4

What effect does a water solvent have on the membrane structure

Answer 4

Water maintains membrane structure
Polar solvent, ∴ interacts with charged phosphate group on phospholipids
Causes phosphate heads to face outwards & fatty acid tails inwards
Forms bilayer with hydrophobic core

Question 5

What types of solvent affect membrane structure?

Answer 5

Water
Organic solvents
Alcohol

Question 6

How does an increase in temperature affect the membrane structure

Answer 6

￪ temperature =￪ kinetic energy of phospholipids
Phospholipids vibrate more
Membrane disrupted, bigger gaps
￪ membrane permeability.
Carrier & channel proteins can denature&raquo_space; ￬ membrane permeability