BSC 114 Chapter Notes - Chapter 7: Tonicity, Solution, Lysis
24 Mar 2016
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Document Summary
Selective permeability- allows some substances to cross it more easily than others. Ability of the cell to discriminate in its chemical exchanges with its environment is fundamental to life. Cellular membranes are fluid mosaics of lipids and proteins. Amphipathic- has both a hydrophilic region and a hydrophobic region. Fluid mosaic model- membrane is a fluid structure with a mosaic of various proteins embedded in or attached to a double layer of phospholipids. Membranes with different functions differ in structure and chemical composition. Membrane is held together primarily by hydrophobic interactions. Integral proteins- penetrate the hydrophobic interior of the lipid bilayer. Peripheral proteins- not embedded in the lipid bilayer at all. Appendages loosely bound to the surface of the membrane. Nonpolar molecules can dissolve in the membrane and therefore cross it easily. Transport proteins- allow specific ions and a variety of polar molecules to pass through the cell membrane.
