Biology 2382B Study Guide - Partition Coefficient, Cytoskeleton, Beta Barrel
Document Summary
The exoplasmic side of the membrane can be called different things luminar, extracellular. Integral proteins: always in the same orientation, i. e. cadherins, must have a transmembrane domain must have hydrophobic components. 2 structures formed as a transmembrane domain beta barrel and more commonly a-helix: simple helical structure that spans the transmembrane domain. A-helix transmembrane domain is 20-25 amino acids: also needs cytoplasmic and exoplasmic domain the sizes can vary. Ideally part is extracellular and one is cytoplasmic: hydrophilic (charged) residues. Charged amino acids in the cytosolic side of most transmembrane proteins. Function: if you try to pull the protein from the extracellular side, the charged aa will resist being pulled in the transmembrane region. This anchors the protein there: exoplasmic domain can be glycosolated (sugars can be added) i. e. found in the lumen of er and golgi. The proteins that are modified can be glycosylated because they are in the exoplasmic section.