Protein Structure & Function: Overview of Amino Acids, Structures & Enzymes - Prof. Clint , Study notes of Genetics

Download Protein Structure & Function: Overview of Amino Acids, Structures & Enzymes - Prof. Clint and more Study notes Genetics in PDF only on Docsity! GENE 310 ; Lecture outline for protein structure Proteins are polymers (chains) of amino acids • 20 different amino acids are used to make proteins all have an amino (NH3) group and a carboxylic acid (COOH) they differ in the "side chain" which can be simply an H (glycine) or a complex double ring structure most side chains are uncharged, but two are acidic (-) and 2 basic (+) at typical cell pH values two amino acids contain sulphur (S) in the side chain the protein is formed by linking the N in the amino group of one amino acid to the C in the COOH of the previous amino acid. this creates a peptide bond, and the units are also called peptides the chains vary in length from a few to thousands of units • the primary structure of a protein is the sequence of amino acids the "beginning" of the chain has a free NH3 (amino terminal) and the "end" of the chain has a free carboxyl COOH ie. there is a "direction" proteins are very information-rich molecules • secondary structure results from natural folding where helixes, sheets, barrels etc. that form due to interactions within the chain of amino acids • tertiary structure refers to the 3-D structure that may also include cofactors • quaternary structure refers to the fact that many proteins contain multiple polypeptide chains Enzymes are proteins that catalyze specific metabolic reactions • each reaction requires a different enzyme • each enzyme is the product of one or more genes • an active site (often a groove or cleft in the surface of the 3-D folded protein) acts as a "magnet" for the substrates in the reaction