IUB BIOL-L 112 - Protein Structure and Function (2 pages)

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BIOL L 112 1nd Edition Lecture 6 Outline of Last Lecture I Proteins II Amino Acids A Nonpolar Side Chains B Polar Side Chains C Electrically Charged Side Chains Outline of Current Lecture I Protein Structure A Primary Structure B Secondary Structure C Tertiary Structure D Quaternary Structure II Protein Folding in the Cell III Nucleic Acids IV DNA V RNA Current Lecture I The structure of a protein is a unique 3D shape and plays a large role in function There are four different levels of protein structure primary secondary tertiary and quaternary The structure of a protein is affected by the folding that occurs as the protein is synthesized within a cell and the physical chemical conditions of its environment These conditions include pH salt concentration solvent heat and chemicals present that may disrupt bonding A The primary structure of a protein is linear and involves only the covalent bonds between the amino acids This sequence of amino acids is genetically determined and difficult to break B The secondary structure of a protein is held together by hydrogen bonding between parts of the polypeptide backbone NOT the side chains It causes coils and folds in the structure There are two types of secondary structures alphahelix coils and beta pleated sheets C The tertiary structure gives a protein its unique shape because of the interactions between atoms on the side chains of the amino acids It involves both weak and These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute II III IV V strong chemical bonds in order of increasing strength hydrophobic interactions hydrogen bonding ionic bonds and disulfide bonds D The quaternary structure is the bonding between 2 or more polypeptides These bonds are due to interactions between side chains of amino acids and include hydrophobic interactions hydrogen bonds ionic bonds and disulfide bonds Protein folding within a cell is a