BIOL 1101 Chapter Notes - Chapter 4: Alpha And Beta Carbon, Peptide Bond, Alpha Helix
3 Dec 2016
School
Department
Course
Professor
Document Summary
General structure of amino acid: central carbon atom (alpha carbon, amino group (-nh2, carboxyl group (-cooh, hydrogen atom (-h, side chain (r group) R groups: chemically diverse, grouped according to their properties (particularly hydrophobic vs. hydrophilic, strongly in uence how polypeptide folds, hydrophobic amino acids: Non-polar r groups composed of hydrocarbon chains of uncharged carbon rings. Proline: r group linked back to the amino group > linkage creates a bend in the polypeptide chain and restricts the rotation of the c-n bond, imposes constraints on protein folding in its vicinity. Cysteine: -sh group, can form an s-s disul de bond (covalently joins the side chains) > these bonds are stronger than the ionic interactions of other pairs of amino acids + can form cross bridges. Polymers: ends are chemically distinct from each other. Protein coding= turns an unorganized polypeptide strand into a complex and useful 3-
