Effects of temperature and pH on the enzymatic activity of a-amylase IntroductionEnzymes are fundamental molecules within organisms. They are the biological catalysts of cells; increasing the speed of biochemical reactions, ensuring the satisfaction of metabolic needs. These molecules are identified as globular proteins with three-dimensional structure and are composed of one or more polypeptide chains. The polypeptide chain or chains within an enzyme are folded to form a specific active site. Each structured active site is different and only catalyzes a certain substrate that adapts; this is known as the lock and key model (Cooper, 2000). Enzymes reach the highest reaction rate when they are in optimal conditions; these conditions include internal temperature and pH levels. When one of these conditions is not in the optimal range, the active sites of the enzyme can be denatured, thus preventing the substrate from catalyzing and reducing the reaction rate (Berg, Tymoczko, Stryer, & Stryer, 2002). The substrate catalyzed in this experiment is starch. Starch is a polysaccharide carbohydrate consisting of many glucose molecules linked together in linear or branched chains by glycosidic bonds. The enzyme used in this experiment is α-amylase, which simulates the salivary enzyme that catalyzes starch present in human saliva. The purpose of this experiment was to investigate how changes in pH and temperature affect the reaction rate of A-amylase enzymatic activity in a starch substrate. α-amylase reaction rates were observed using iodine. During the experiment the enzymatic reaction of starch created a maltose product. Iodine reflects a blue color when in contact with a starch molecule and converts to a yellowish color when in the medium of paper. Fire and pH are just some of the conditions that manipulate enzyme activity. The concentration of the enzyme is directly related to the rate of reaction up to the saturation point of the enzyme. Enzyme saturation is the point at which the amount of enzyme (catalysis) and substrate are in equilibrium, meaning that all enzymes are working and the maximum reaction rate has been reached. Enzyme concentration is just one of many other factors that can manipulate enzyme activity, other factors include substrate concentration, inhibitors, and viscosity effects. To gain a deeper understanding of enzyme specificity, these factors should be studied (Worthington Biochemical Corporation, 2015). Determining the effects of changing pH and temperature on the enzymatic activity of α-amylase highlighted the specific nature of the enzymes and how they can only complete biochemical reactions under optimal conditions.