Membrane As Permeability Barriers

Question 1

Passive transport is dependent on?

Answer 1

Permeability and concentration gradient

Question 2

What can diffuse across the bilayer and what can’t?

Answer 2

Can- hydrophobic molecules, small uncharged polar molecules

Can’t- large uncharged polar molecules, ions

Question 3

What are permeability coefficients?

Answer 3

Amount of permeability

Question 4

Transport processes have important roles such as.?

Answer 4

Maintenance of ionic composition
Maintenance of intracellular pH
Regulation of cell volume
The generation of ion gradients necessary for the electrical excitability of nerve and muscle

Question 5

What is the direction of osmosis determined by?

Answer 5

Comparing total solute concentration

Question 6

Define isotonic hypertonic and hypotonic

Answer 6

Isotonic- equal solutes equal water
Hypertonic- more solute less water
Hypotonic- less solute more water

Question 7

Define osmolality?

Answer 7

When the concentration of solution is expressed in osmoles per kilogram of water

Question 8

What is osmotic pressure?

Answer 8

The pressure required to stop the flow of water

Question 9

Features of aqua Porins channels?

Answer 9

Integral membrane proteins are tetrameric has 13 or more isoforms permit rapid water diffusion above the rate of passive diffusion through the lipid bilayer