Material transport

Diffusion

through PERmeable
membrane

for solutes

Nernst's partition coefficient

D = P × A × (Δc / d)
mol / s

D = diffusion speed
P = permeability coefficient
A = area of the membrane
Δc = change in concentration

K = c (A in phase 1) / c (A in phase 2)

Osmosis

on SEMIpermeable
membranes

Osmolarity

Osmolality

based on the volume

based on the mass

c (osmotic) = n (osmotic) / V (solvent)

b (osmotic) = n (osmotic) / m (solvent)

Osmotic pressure

p osmotic = σ × c × R × T
(Pa) (Van't Hoff's law)

p osmotic = osmotic pressure
σ = reflection coefficient
c = molar concentration
R = gas constant
T = temperature

σ = 0

permeable membrane

σ = 1

impermeable membrane
(Semipermeable membrane)

Tonicity

gradient of osmotic pressure

Isotonic

equal

Hypertonic

greater

water flows out
cell shrinks