BIOC 4580 Lecture Notes - Lecture 4: Vacuum Chamber, Micelle, Sphingolipid
31 Jan 2017
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Document Summary
Pc vs spm the overall shapes of lipids are important. Pc & spm look similar as space-filling models but have overall different shapes. Both have hydrophobic tails, choline headgroups; difference lies in tail structure. Unusual non-lamellar phases such as hexagonal hii are formed as intermediates in membrane fusion, for example. We can induce expanded and compressed phases by excluding water. If we do this in 3-d space, we get hexagonal phases. Lipids have a variety of fast and slow motions within bilayers, some affected and/or effected by proteins. Some of these motions involve acyl chains (kinking) and thus affect packing. Phases represent the degree of packing, and phase transitions of membranes depend on lipid composition and can be monitored by techniques such as differential scanning calorimetry (dsc) Membrane microdomains and lipid motions can be studied by techniques such as fluorescence microscopy of giant unilamellar vesicles, and computational molecular dynamics simulations.
