Chemistry 1027A/B Lecture Notes - Peptide, Disulfide, Collagen
Document Summary
Amino acids found in proteins are only in the l-form. When deroo talked about beta-sheet, she meant that beta-sheet is 1 polypeptide chain folded back on itself. In an oxidative environment, 2 cysteine side chains will form a disulfide bond. This is a reversible rxn under reducing environment. Domain is a part of a single polypeptide that has folded around in a certain way. This is different from subunits, (quaternary) subunits are a polypeptide chain of its own that binds to other polypeptide chains. Glycine has to be every 3rd residue b/c it"s small. The fact that it"s small makes it possible for the three helices to approach each other closely. In a collagen molecule, they are crossed linked with lysine residues side chains of adjacent molecules.