Chapter 7 Notes

Chapter 7 Notes - Chapter 7 Membrane Structure and Function...

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Chapter 7 Membrane Structure and Function Overview: Life at the Edge The plasma membrane Is the boundary that separates the living cell from its nonliving surroundings The plasma membrane exhibits selective permeability It allows some substances to cross it more easily than others Concept 7.1: Cellular membranes are fluid mosaics of lipids and proteins Phospholipids Are the most abundant lipid in the plasma membrane Are amphipathic, containing both hydrophobic and hydrophilic regions The fluid mosaic model of membrane structure States that a membrane is a fluid structure with a “mosaic” of various proteins embedded in it Membrane Models: Scientific Inquiry Membranes have been chemically analyzed And found to be composed of proteins and lipids Scientists studying the plasma membrane Reasoned that it must be a phospholipid bilayer The Davson-Danielli sandwich model of membrane structure Stated that the membrane was made up of a phospholipid bilayer sandwiched between two protein layers Was supported by electron microscope pictures of membranes In 1972, Singer and Nicolson Proposed that membrane proteins are dispersed and individually inserted into the phospholipid bilayer Freeze-fracture studies of the plasma membrane Supported the fluid mosaic model of membrane structure
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The Fluidity of Membranes Phospholipids in the plasma membrane Can move within the bilayer Proteins in the plasma membrane Can drift within the bilayer The type of hydrocarbon tails in phospholipids Affects the fluidity of the plasma membrane
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This note was uploaded on 04/23/2008 for the course SCI 1406 taught by Professor Sheffield during the Spring '08 term at Tarrant County.

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Chapter 7 Notes - Chapter 7 Membrane Structure and Function...

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