Membrane Permeability

membrane permeability

SMALL, NONPOLAR molecules can freely pass through the membrane. LARGE, POLAR molecules and SMALL IONS cannot freely pass through

osmosis

process of water diffusing across the membrane

isotonic solution

equal concentration of solute inside and outside the cell

hypotonic

LOWER solute concentration outside the cell; water flows in

hypertonic

HIGHER solute concentration outside the cell; water flows out pa

passive transport

NO energy input, moves molecules down concentration gradient

active transport

requires energu, moves substances against concentration gradient

simple diffusion

molecules move freely through the cell membrane f

facilitated diffusion

molecules move through channels or carries in the membrane, no energy required

primary active transport

uses energy directly from ATP hydrolysis s

secondary active transport

uses energy from electrochemical gradient created by primary active transport