BIO 1140 Lecture Notes - Transatlantic Flight Of Alcock And Brown, Lipid Bilayer, Semipalmated Sandpiper
22 Dec 2012
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Document Summary
Fluid-mosaic model proposed in 1972 by singer and nicholson. Important for defining the boundaries of cells and organelles (in eukaryotes) due to their structure and ability to be a permeability barrier. The interior environment can be different from the exterior environment because of the cell membrane. Membrane proteins regulate what crosses the membrane in and out. Important for organizing enzymes and other structures within the cell. Important for cell to cell recognition and forming attachments (i. e. : cytoplasmic links via gap junctions and plasmodesmata) The structure of the membrane reflects it function. E. g. : inner mitochondrial membrane has a 76% protein and 24% lipid composition (protein-rich membrane for the electron transport chain) while the plasma membrane of a schwann cell is 18% protein and 82% lipid (for insulation and sultatory conduction) Postulates that the membrane is a lipid bilayer with proteins studded into it.
