MBB 222 Lecture Notes - Lecture 7: Acid Dissociation Constant, Cell Nucleus, Guanidine
Document Summary
>95% of all drugs target proteins exhibit more sequence and chemical complexity than dna or rna. Properties and structure defined by the sequence and side chains of their constituent amino acids. Secondary structure: -heli(cid:272)es, -sheets, turns, loops (h bonds only) Tertiary structure: protein folding, side chains and backbone interactions (electrostatic, h-bonds, and van der waals) Quaternary structure: assembled complex of more than one protein. The folded protein structure is stabilized by a variety of weak chemical interactions, and, in some cases, covalent (disulfide) bonds between cysteine residues. There are 20 different naturally-occurring amino acids, each with a different r-group or side chain (aka residue, side arm, side group, etc. E(cid:448)er(cid:455) a(cid:373)i(cid:374)o a(cid:272)id has a(cid:374) (cid:272)ar(cid:271)o(cid:374) (cid:894)c (cid:895) (cid:272)o(cid:448)ale(cid:374)tl(cid:455) atta(cid:272)hed to four disti(cid:374)(cid:272)t substituents: an amino (amine) group, a carboxyl group, a hydrogen and a side chain. C has sp3 hybridization, so it has tetrahedral geometry 4 single (s) bonds at 109. 5 to each other.