LIFESCI 3 Chapter Notes - Chapter 4.1: Disulfide, Amine, Histidine
Document Summary
Primary structure of a protein: sequence of amino acids that make up the polypeptide chain. Amino acid: central carbon bonded to h, amino group, carboxyl group, and side chain. Abbreviated using a 3-letter name or one letter symbol. Pka of side chain is lower than ph of surroundings. Overall charge of protein is due to side chain groups. Tend to cluster inside proteins and stabilize structure through hydrophobic effects. Glycine only has 1 h as side chain contributes little to hydrophobic effect. Interact with water or atoms in other side chains through h-bonds. Two cysteine residues can be oxidized to form a disulfide bond. Lysine, arginine, and histidine have positive charge at ph 7. 0. Aspartate and glutamate have negative charge at ph 7. 0. Charged side can form h bonds and ionic interactions with amino acids of opposite charge. Tyrosine"s hydroxyl group and tryptophan"s nitrogen can form h bonds. Amino acids are connected in a polypeptide chain.
