CHEM4465 Lecture Notes - Scrapie, Missense Mutation, Anfinsen'S Dogma
Document Summary
They participate in cell regulation at all levels. They share a common structural feature: all are linear polymers of amino acids. Examples of protein function: catalysis, transport and storage, coordinated motion, mechanical support (why we don"t dissolve), organism host defenses, growth and differentiation, communication. Ile side chain important for protein stability. Has imidazole (ring with 2 n) can donate or receive h functions in acid/base catalysis, found in enzymes can bind to metal ions: lys has nh3. + at epsilon c highly protonated doesn"t lose h until very high ph; found in histones (bind dna: arganine side chain has quanidino group. Arg + os nitric oxide, a vasodilator. Cooh ionizes and gives a h+ and a conjugate base (coo-) Amino ionizes and retain a h: this is called a zwitterion, an ampholyte"s isoelectric point (point at which net charge is zero) = average of pka1 and pka2. **the side chains of amino acids make them chemically diverse**
