KAAP309 Lecture Notes - Lecture 2: Lipid Bilayer, Electric Potential Energy, Cell Membrane
8 Sep 2016
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Document Summary
The three main components of a human cell: Plasma membrane - flexible, semi-permeable outer boundary. Nucleus - control center responsible for all cellular activity. *lipid bilayer constructed largely of phospholipids and smaller portions of glycolipids and cholesterol* Phospholipids: polar, charged head that is hydrophilic and uncharged, nonpolar tail that is hydrophobic. Glycolipids: lipids with attached sugar groups (5% of membrane lipids) Cholesterol: polar and nonpolar regions; wedge between phospholipid tails and stabilize the membrane (20% of membrane lipids) Transmembrane proteins firmly inserted into the lipid bilayer that span the entire membrane and protrude on both sides (contains hydrophilic and hydrophobic regions) Transport: form channels for small water-soluble molecules to move through; carriers bind to a substance and move it through the membrane. Receptors: detect hormones or other chemical messengers and relay: peripheral proteins messages. Attached loosely to integral proteins and are able to be easily removed. Provide support to the membrane from its cytoplasmic side.
