Lec 4, 5 notes

Lec 4, 5 notes - Lecture 4: Cell Structure and Function...

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Lecture 4: Cell Structure and Function Lecture 5: Membranes and Transport: Basic Properties of Membranes I. All organisms consist of cells A. Prokaryotic 1. Allows for compartmentalization of function II. Plasma Membrane B. Controls transport of materials into and out of the cell w/ a selective barrier 1. Relative permeabilities: a. Hydrophobic molecules (i.e. O 2 , CO 2 , N 2 ) > b. Small uncharged polar molecules (i.e. H 2 O, glycerol): need special channels, > c. Large, uncharged, polar molecules (i.e. glucose, sucrose) > d. Ions (i.e. H + , Na + , NCO 3 - , Ca 2+ ) e. polar, large, and charged are least likely to cross 2. Diffusion: molecules move along the concentration gradient a. Net directed movement of molecules/ions driven by thermal energy b. Spontaneous, passive 3. Osmosis: diffusion of water a. Hypertonic solution (w/ respect to inside) water out, membrane shrinks b. Hypotonic water diffuses in, membrane swells, may burst if it is an animal cell
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This note was uploaded on 10/13/2008 for the course BIO 150 taught by Professor Schmidt during the Spring '08 term at SUNY Stony Brook.

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Lec 4, 5 notes - Lecture 4: Cell Structure and Function...

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