BIO 1140 Lecture Notes - Lecture 6: Microtubule, Beta Sheet, Transmembrane Protein
8 Mar 2016
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Document Summary
Outer limit of the cytoplasm responsible for regulation of substances moving in & out of cells. Allows for the uptake of key nutrients and elimination of waste, while maintaining a protected enviro for cellular processes to occur. Internal membrane resulted in compartmentalization of processes and increased complexity fluid mosaic model : Proposes that the membrane consists of fluid phospholipid bilayer in which proteins are embedded and float freely. Proteins and components in one half of the lipid bilayer are different than the other half. Reflects differences in functions performed by each side of the membrane. Freeze-fracture technique : block of cell is rapidly frozen by dipping it into liquid nitrogen, fractured with knife splitting the bilayer into inner and outer halves, exposing membrane interior. Particles visible in the exposed membrane interior are integral membrane proteins. Membrane proteins rapidly migrate over surface of hybrid cell. Phospholipids are the dominant lipids in the membranes.
