Primary, Secondary, Tertiary and Quaternary Structures of Proteins

Protein structure depends on its amino acid sequence and local, low-energy chemical bonds between atoms in both the polypeptide backbone and in amino acid side chains. Protein structure plays a key role in its function; if a protein loses its shape at any structural level, it may no longer be functional. Primary structure is the amino acid sequence. Secondary structure is local interactions between stretches of a polypeptide chain and includes α-helix and β-pleated sheet structures. Tertiary structure is the overall the three-dimension folding driven largely by interactions between R groups. Quaternary structures is the orientation and arrangement of subunits in a multi-subunit protein. Problem: Which of the following best describes the quaternary structure of a protein? A) How the polypeptide chains fit together B) The layout of alpha-helices and beta-sheets C) The four parts of a protein’s amino acid sequence D) The sequence of nucleic acids E) The polypeptide chain’s complete 3-D structure #protein #proteinStructure #proteinSequence #polypeptide #NikolaysGeneticsLessons #aminoAcid #peptide #disulfideBridges #covalentBounding #ionicBounding #hydrophobicInteraction #proteinFolding #aminoAcids #proteins #Polypeptides #ImidazolRing #Histidine #polypeptideChain #oligopeptide #hydrolysesSynthesis #condensationReaction #condensationSynthesis #peptides #globularProteins #fibrousProteins #Genetics