BIOL 1201 Chapter : 1 31 12
Document Summary
Tertiary structure: folding into a 3-dimensional structure, folding is due to the properties and interactions of the r groups (amino acid side chains) R groups: hydrophobic and hydrophilic properties, hydrophobic r groups-buried in the interior of the protein, hydrophilic r groups interact with one another or are on the surface interacting with water. Stabilizing tertiary structure: weak- hydrogen bonds, ionic reaction, hydrophobic and van de waals interactions, strong disulfide bridge. Disulfide bridges: sh groups of two cysteine form covalent bond, stabilizes tertiary structure. Quaternary structure: multiple polypeptide chains (subunits) fit together to form a larger protein, can be identical subunits or different polypeptide chains. Sickle-cell hemoglobin mutation alters primary, tertiary, and quaternary structures. Native and denatured proteins: native- properly folded and functional, denature- unfolded and does not function. Roles of weak bonds in biological systems: easily made and broken at physiological temperatures, provide specificity, attract and attach substrates to enzymes, determine molecular shape- a compromise between backbone and side groups.
