5.3 -Diffusion

Question 1

What type of transport is diffusion?

Answer 1

Passive transport (doesn’t require any extra energy)

Question 2

What is diffusion?

Answer 2

The net movement of particles from high concentration to low concentration until there is an equilibrium

Question 3

Factors affecting the rate of diffusion

Answer 3

Temperature:
Increases KE so move quicker

Concentration difference:
Increase the concentration gradient, more particles move

Surface area:
More particles can get through at once if its large

Distance:
The larger he distance, the less movement the particles have

Size of particle:
The larger the particle the slower the rate of diffusion

Chemical nature of particle:
Non polar particles diffuse faster than the polar ones

Question 4

What type of particles can simply diffuse?

Answer 4

Small particles
Non polar (because membrane is hydrophobic )

Question 5

What does facilitated diffusion involve?

Answer 5

• Passive transport but molecules use transmembrane proteins to move in + out of the cell because they cannot interact with the hydrophobic tails of the bilayer
• carrier proteins (change shape for different molecules
• channel proteins (for ions + polar molecules)