Osmosis Flashcards
Diffusion
The movement of molecules across a selective (semi-permeable) barrier from high concentration to low
Selective (semi-permeable) barrier
A barrier that allows water molecules to pass through, but
not most of the molecules dissolved in the water
Osmosis
The diffusion of water molecules across a selective (semi-permeable) barrier from high concentration to low concentration
Solutes
Molecules that are dissolved in water
What is the concentration of water determined by?
The concentration of solutes in the water
Solute potential
A measure of the concentration of solutes dissolved in water
Does pure water have solutes?
No
When are water molecules most concentrated?
At 0
What does adding solutes do?
It lowers water concentration (negative value)
As solute concentration increases, ____ ________ _______.
water concentration decreases
Water moves from areas of ______ to areas of ______.
higher concentration; lower concentration
Plasma Membranes
Semi-permeable barriers
Brain Capillaries
Fine blood vessels that feed brain tissue
Molecules can not pass between the cells through _______ _______.
Intercellular junctions
What do cells depend on to stay alive?
Regulated movement of water molecules across the PM
