Amylase Activity Lab Report

The Determination of the Effect of pH on Amylase Activity
Grace Chung
Abstract: Amylase is an important enzyme in the human body as it allows for the consumption of starch by breaking the polysaccharide down into maltose units. All enzymes, including amylase, function best at a certain optimal pH. Therefore, in this experiment, the effect of different pHs on the reaction rate of amylase is studied. It was hypothesized that the amylase-starch reaction would proceed fastest at a pH closest to that of the body, or 7.0, since that is where the enzyme normally functions. Lower and higher pHs would cause the enzyme reaction to proceed slower. In order to test the hypotheses, several reactions of amylase and starch solutions with varying pHs
They are able to catalyze reactions in the body, meaning that they lower the activation energy of reactions and allow them to proceed without being consumed in the reaction itself. This is important because when the activation energy is lowered for a particular reaction, the reaction is able to happen more quickly. Without these crucial macromolecules, organisms would not be able to function very efficiently and reactions would take an extremely long time to happen. In order to catalyze reactions, the substrate, the reactant the enzyme performs on, must first bind to a specific area on the enzyme called the active site. It is currently believed that there are several different methods in which an enzyme lowers the activation energy of a reaction and therefore speeds up the process. To begin with, by binding with the substrates, the enzyme is able to bring the different reactions closer together, making it easier for a reaction between them to occur. In addition, sometimes the enzyme changes its shape around the substrate in an induced fit in order to stretch or bring out certain groups on the substrate. This makes it easier for the enzyme to catalyze a reaction. Sometimes, the active site even participates directly in the reaction between reactants by creating brief covalent bonds between the enzyme and its
It was also predicted that the enzyme would function slower in pH’s both lower and higher than 7.0. The results of this experiment supported the hypotheses that had been made (stated above). The optimal pH of an enzyme varies depending on where it is normally found. Amylase is found in saliva, which has a pH range from slightly acidic (6.0) to neutral (7.0). Amylase enzymes are proteins made up of amino acids. Because pH affects the molecular structure of proteins through the making and breaking of bonds, if amylase is placed in a strongly acidic or strongly basic solution, its molecules would lose or gain electrons or protons which affects structure and charge of the amino acids, and hence can influence structure and function of an enzyme. At pHs higher and lower than that of the optimal point, the structure of amylase begins to straighten out due to the lack of bonds and the shape of the active site becomes distorted, making it difficult for the substrate to bind. When the pH reaches a certain high or low point, the structure of the enzyme completely transforms which causes it to denature. Therefore, to a point (to be discussed in more detail below) increasing pH will cause substrates to bind to active sites more frequently. This relationship can be seen as