BIO 201 Lecture Notes - Lecture 12: Fluid Mosaic Model, Benzene, Lipid Raft
27 Feb 2017
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Document Summary
~70 - 80 angstroms thick ~2x length of a typical phospholipid. Railroad track appearance in transmission electron microscopy (tem) Polar groups want to be in polar environment while hydrophobic groups want to be away from polar environment. Like a sandwich (polar hydrophilic head groups make up bread while nonpolar hydrophobic tails make up filling) Measuring membrane fluidity (fluorescence recovery after photobleaching - frap) Unlabeled cell becomes labeled with fluorescent dye. Dye can"t be unbleached and fluorescent again. Laser hits area on membrane and bleaches it. After some time, bleached area seems to become unbleached again. Due to lipids from outside of bleached spot diffusing and filling in area. Steep curve - fast recovery (high fluidity) Shallow curve = slower recovery (low fluidity) High tm less fluid; better at high temp. Low tm more fluid; better at low temp. Has little oh group - tiny polar component faces ecf/icf.
