BIOL 1406 Chapter Notes -Transmission Electron Microscopy, Endoplasmic Reticulum, Lipid Raft
Document Summary
Phospholipids: 2 fatty acids, 1 phosphate group. Cell membrane has 4 components: phospholipid bilayer, transmembrane protein; transport & communicate. * plasma membrane is not homogenous, contains microdomains w/ lipids called lipid rafts (forms ordered structure which results in dynamic nanometer sized, sterol) Transmission electron microscope (tem) and scanning em allow membrane structure to be seen. 3 classes: glycerol phospholipids (most diverse), sphingo, sterols. Phospholipids layers, driven by the tendency of water. A lipid bilayer is stable due to water"s affinity for hydrogen bonds that never stops. Water has no effect on mobility of phospholipids/non-lipids. Glycerol that are saturated (mono cis-unsaturated- make membrane less fluid/ 2x bond introduced by fatty acids = more fluid. Endoplasmic reticulum, unsaturated, thinner than plasma membrane, Plasma membrane is given fluidity by addition of cholesterol, its rigid but fluid. Endoplasmic reticulum is also fluid but has more curves and is cone shaped, also does not have cholesterol.
