BSCI 207 Lecture Notes - Lecture 10: Gibbs Free Energy, Mass Diffusivity, Spontaneous Process
26 Jan 2016
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Document Summary
For organisms, diffusion is almost never an important factor on a larger scale. Molecules follow a straight path until they hit other molecules/something else. Random molecular motion which redistributes molecules from an area of high concentration to an area of low concentration. Molecules spread out by chance/because they"re moving randomly. Not because they want to or purposefully spread out/distribute. Diffusion is an emergent property due to randomness. Diffusion rate is proportional to concentration gradient. This gradient is what causes the net movement of molecules. G can be thought of as a measure of instability. Systems tend toward stability, or lower g. Higher free energy/g = less stable = greater work capacity. Diffusion is a spontaneous process drives by increase in entropy. Organisms rely on diffusion to move, retain, and get rid of molecules. Flux is the number of molecules moving through an area per unit time. A decrease in concentration gradient means a decrease in flux.
