2.4 Membranes

Question 1

Name some functions of membrane proteins

Answer 1

Hormone binding sites
Immobilised enzymes
Cell adhesion
Cell-to-cell communication
Channels for passive transport
Active transport pumps

Question 2

Define ‘diffusion’

Answer 2

The passive movement of particles from a region of high concentration to a region of low concentration

Question 3

Define ‘osmosis’

Answer 3

The passive movement of water molecules, across a partially permeable membrane, from a region of lower solute concentration to a region of higher solute concentration

Question 4

Give an example of symport

Answer 4

The Na+/K+/Cl- pump in the kidney

Question 5

Give an example of an antiport

Answer 5

The Na+/K+ pump in neurons