1. Definitions Solute Solvent Osmosis Osmotic Pressure Osmolarity Hyperosmotic Hypoosmotic

2. Solutes are dissolved particles in solution (any type) Osmotic pressure depends on the number of solutes/unit volume (rather than chemical nature of solutes)

3. As this column rises higher, it will exert increasing pressure. At some point that hydrostatic pressure will reach an equilibrium, at which point no more net water will move across the semi-permeable membrane. This pressure is the ‘osmotic pressure’ of the starting solution on the right. Osmotic flux of water: --which way will the water move? -- Why is there net water flux tothe right?

4. isosmotic Solutes are dissolved particles in solution (any type) (osmotic pressure is equal)

5. Solutes are dissolved particles in solution (any type) hypersmotic (higher osmotic pressure) hyposmotic (lower osmotic pressure)

6. Water always moves from an area of low osmotic pressure to an area of high osmotic pressure Hyposmotic (lower osmotic pressure) Hyperosmotic (higher osmotic pressure) osmotic pressure: the pressure of water to enter, given the solute concentration Osmosis: movement of water from an Area with lower osmotic pressure to Higher osmotic pressure

7. Osmolarity = concentration of solutes in a solution Osmolarity vs. Molarity: 150 mMol sucrose= 150 mOsm sucrose 150 mMol NaCl= 300 mOsm NaCl Osmotic pressures are generally described in osmolar units: