Lipi las Amphipathic Spontaneously form lipid bilayers
12 Lipids ➢ Amphipathic ➢ Spontaneously form lipid bilayers
Lipids are amphipathic hydrophilic Pol -N(,3 head CHOLINE hydrophilic)PHOSPHATE GLYCEROL hydrophobic tails 998GA
13 Lipids are amphipathic Polar
Lipids spontaneously form structures 會 (A) 1 nm a lipid bilayer is a stable, low energy structure Self sealing structure/eliminate free edge Exclusion of Lipids from Water. not lipid association 14
14 Lipids spontaneously form structures A lipid bilayer is a stable, low energy structure Self sealing structure/eliminate free edge What drives this structured association? Exclusion of Lipids from Water… not lipid association
Lipid bilayers will form closed structures ENERGETICALLY UNFAVORED > compartments planar phospholipid bilayer e behave as 2d fluids with edges exposed to water Self seal if disrupted sealed compartment formed by phospholipid bilayer ENERGETICALLY FAVORED
15 Lipid bilayers will form closed structures ➢ compartments ➢ behave as 2D fluids ➢ Self seal if disrupted
Lipids are effective barriers to some compounds SMALL HYDROPHOBIC MOLECULES№2 hydrophobic compounds benzene can reach equilibrium SMALL UNCHARGED H20 POLAR glycerol quickIy MOLECULES ethanol unfavored LARGER amino acids UNcharGed glucose POLAR nucleotides compounds can be MOLECULES brought across by HT Na HCO K IONS Ca2+ Cl transport proteins Need for… ransport synthetic Mechanisms lipid bilayer
16 Lipids are effective barriers to some compounds ➢ hydrophobic compounds can reach equilibrium quickly ➢ “unfavored” ➢ compounds can be brought across by transport proteins Need for …..Transport Mechanisms