Whatarethedifferencesbetweenosmosisanddiffusion.pptVIP

What are the differences between osmosis and diffusion? What regulates diffusion and osmosis? What is the difference between osmolarity and osmolality? Iso-osmotic, hyper-osmotic and hypo-osmotic Isotonic, hypertonic and hypotonic? Be able to do a calculations of solutions (A vs. B): Molarity, millimolarity, osmolarity, milliosmolarity, water movement Which solution is: Isotonic, hypertonic and hypotonic? MOLARITY VS MOLALITY One mole of a solute (MW) dissolved and made up in 1 liter of solvent (1000ml) is a 1M (one molar solution) One mole of a solute (MW) dissolved in 1 kilogram of solvent (1000g) is a 1m (one molal solution) MOLARITY/MOLALITY 1M = One molar 1m = One molal 1M = 1000mM (millimoles) 1m = 1000mm (millimolals) Assumed equal in all our examples!!! OSMOTIC PRESSURE The greater or larger the [solute] of a solution, the greater the osmotic pressure Osmotic pressure is measured is measured as Osmolarity or Osmolality (remember equal for us because everything dissolves completely in our solvent (water) 1 Osm = 1 osmole 1 Osm = 1000 mOsm (milliosmoles) Same units used for Osmolality and Osmolarity!!! OSMOLARITY/OSMOLALITY Depends on the ratio of solute to solvent The higher the [solute] the higher the osmotic pressure BUT MAJOR DIFFERENCES BETWEEN SALTS AND SUGARS!! SUGARS (glucose, sucrose etc.) Do NOT ionize (dissociate) when they are dissolved in water!! IM glucose ------ = 1Osm (placed in H20) SUGARS (glucose, sucrose etc.) Do NOT ionize when they are dissolved in water!! IM glucose ------ = 1Osm (placed in H20) SALTS (NaCl, CaCl2 etc.) DO ionize or dissociate!! IM NaCl ------ 1 Osm Na+ plus 1 Osm Cl- (placed in H20) (each exert own osmotic pressure) = 2 Osm OSMOSIS Osmosis is the movement of water (solvent) across a semi-permeable membrane from a region of high solvent concentration [low solute] to a region of low solvent [high solute]. OSMOSIS Water is “pulled” across a semi-permeable membrane to