MCDB 1150 Lecture Notes - Lecture 24: Lipid Bilayer, Semipermeable Membrane, Osmosis
17 Nov 2016
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Document Summary
Overhead explaining net diffusion vs. diffusion on d2l. When molecules are diffusing, if the membrane is permeable, movement is random. Different solutes on opposite sides of a lipid bilayer. Each undergoes a net movement along its own concentration gradient. Solutes diffusing back and forth across the membrane at equal rates. Change in concentration, looks like they went one way but they just diffused. Concentration number of molecules per unit of volume. Rate of movement of water molecules across a membrane not number of water molecules move. Rate of movement of individual water molecules across the membrane is not equivalent to the number of water molecules moving across the membrane per unit time. Higher concentration of solute on one side of bilayer. Solute cannot cross bilayer (impermeable to solute) Higher concentration of water on one side of bilayer. Net movement of water from side of low solute concentration (high water concentration to side of high solute concentration (low water concentration)
