Notes on Membrane Structure and Function

*Membrane Structure and Function *Selective permeability- allows some substances to cross it more easily than others *Phospholipids are the most abundant lipids in membranes <Tab/>*An amphipathic molecule (has both hydrophilic and hydrophobic region), proteins too *Overton hypothesized that membranes are made of lipids *Langmuir made artificial membranes by adding phospholipids dissolved in benzene to water *Benzene evaporated, phospholipids remained as a film covering the surface of water with only the …

…Receptor-mediated endocytosis occurs when ligands (extracellular substances that bind to specific receptor sites) cluster into regions of the membrane called coated pits; a fuzzy layer of proteins deepen the pit and form the vesicle; enables the cell to acquire bulk quantities of specific substances; take in cholesteroil for use in the synthesis of membranes and as a precursor for the synthesis of other steroids *cholesterol travels in the blood in particles called low-density lipoproteins (LDLs)