BIOCH200 Lecture Notes - Lecture 8: Acid Dissociation Constant, Zwitterion, Amine
26 Sep 2016
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Biochem 200 - lecture #8 - the amino acids. Proteins communicate, transport, movement, structure, catalysis and do a whole lot of other stuff: the essence of a protein"s function is in its interaction with other molecules, a protein"s function is determined by its structure. Roles are selective: achieve function through structure. Structure can depend on how they interact with other proteins. A generic amino acid at ph 7: zwitterion: a neutral (overall) ion with both + and - charges. The ionization state of amino acids is altered by a change in ph. Cooh coo- + h+ pka 2. Log of dissociation constant ie. pka = -log[ka] When acid is stronger, then equilibrium moves more closer to the dissociation constant. Amino acids are chiral molecules: chiral molecules cannot be superimposed onto its mirror image. Amino acid side chains: only 20 amino acids are commonly incorporated into proteins, classified by chemical properties of their side chains (r group, groups:
