BCH210H1 Chapter 27: R27
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BCH210H1 Full Course Notes
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Can also change to bind s (e morphs ) accepted model. Facilitated diffusion: structure/function of an ion channel, the potassium channel, structure/function of a receptor, the beta-adrenergic receptor. Membrane transport: essential for life, nutrients go in, waste goes out, inorganic ions in and out, some small uncharged molecules freely diffuse across, passive diffusion, most require integral membrane protein transporters, facilitated transport, active transport (uses atp) Passive diffusion: favors small, uncharged, non-polar molecules, diffuse down their concentration gradient. [high] [low: no help from any transporter system. Bilayer permeability: few molecules cross membranes by passive diffusion, larger molecules, charged, polar require a transporter system. Facilitated diffusion/transport: passive diffusion of most molecules is too slow, integral proteins can facilitate diffusion across membrane, in a thermodynamically favorable direction ( g <0, display affinity and specificity for transport species. Facilitated diffusion displays saturation behavior : facilitated diffusion rates displayer saturation behavior similar to substrate binding to enzymes, passive diffusion:
