Movement of molecules from an area of higher concentration to an area of lower concentration |
Movement of solvent molecules from an area of lower solute concentration to an area of higher solute concentration through a semi-permeable membrane |
Can occur in any medium (air, liquid, gas) |
Occurs only in liquid or gas |
Does not require a semi-permeable membrane |
Requires a semi-permeable membrane |
Can occur in both living and non-living systems |
Mainly occurs in living systems |
Does not involve the movement of water molecules |
Involves the movement of water molecules |
Does not require energy |
Does not require energy, but may require pressure |
Examples include the movement of gases in the lungs and the diffusion of perfume in a room |
Examples include the movement of water in plant cells and the movement of water and ions in the kidneys |