CHE 4341 Study Guide - Midterm Guide: Two-Dimensional Gel Electrophoresis, Affinity Chromatography, Enzyme Assay
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Chapter 3 & 4 study guide amino acids & polypeptides. What are some environmental conditions that must be controlled while purifying a protein? ph, temperature, and other conditions such as the presence of degradative enzymes, adsorption to surfaces, isolation procedure, long-term storage, and oxidative reactions. Describe how a protein may be quantified by an assay or by absorbance spectroscopy. A protein may be quantified by measuring the rate at which its substrate is converted to reaction products when an enzyme is present. Enzymes are assayed at their optimum ph and convenient temperatures by direct assay, couple enzyme assay, radioimmunoassay (ria), or an enzyme-linked immunosorbent assay (elisa). The total protein concentration can be measured by absorbance spectroscopy, proteins with aromatic rings absorb. The beer-lambert law can be used to determine the concentration of certain molecules. Explain how salting out is used in protein fractionation. The solubility of proteins is lowered in the presence of salts, an effect called salting out".
