ABSTRACT
The membranes that surround living cells are selectively permeable. This makes osmosis important in biology. Solutions for medical treatment of the eyes and other delicate parts of the body are formulated to have the same osmotic potential as body fluids, as are isotonic drinks. osm otic pressure: the pressure needed to stop osmosis when the solution is sepa rated from pure solvent by a selectively permeable membrane. Osmotic pressure depends on the concentration of solute particles and not on their chemical nature. There is a formula relating osmotic pressure to concentration at a given tempera ture. With the help of this formula osmotic pressure measurements can be used to determine the molar masses of large molecules such as proteins and polymers.
