Definitions

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. Osmotic flux of water: --which way will the water move? -- Why is there net water flux tothe right? As this column rises higher, it will exert increasing pressure. At some point that hydrostatic pressure will reach an equilibrium, at which pointno more net water will move across thesemi-permeable membrane. This pressure is the ‘osmotic pressure’of the starting solution on the right.

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

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

6. Water always moves from an area of low osmotic pressure to an area of high 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 Hyposmotic (lower osmotic pressure) Hyperosmotic (higher osmotic pressure)

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