Chirag Patel Biology 157 Determining the Effect of Varying Substrate Concentration Question: How does concentration of potatoes affect the amount of oxygen produced with hydrogen peroxide and potatoes (enzymes)? Introduction The enzyme used for this experiment is Catalase. Catalase is inside mostly any living organism which uses oxygen. Its job is to break down hydrogen peroxide, into oxygen and water. (Formula) 2H2O2 —> 2H2O + O2 (lab manual). There are limiting factors which if altered, can alter the procedure of the reaction, such as temperature, pH, and the concentration of either the enzyme or the substrates.
Enzymes are specialized class of protein that acts as catalysts for the chemical processes within our cell which may occur slowly. To speed up these chemical reactions and for proper function, each enzyme binds with a substrate. The substrate binds to the active site of the enzyme. This union of substrate to the active site lowers the activation energy. This energy reduction allows reactions to occur at faster rate. The enzyme will not function properly, if the shape of the enzyme is denatured or the binding of substrate and enzyme is interrupted.
There are several independent, and dependent variables that affect the enzyme activity. Some of these variables are temperature, PH, salt concentration and enzyme and substrate concentration. Materials and Methods Equipment and Supplies needed * Catalase activity measuring apparatus * Potatoes * Blender * Scale * Knife * 1000 ml plastic beaker * Hydrogen peroxide solutions (3%,1%,. 3%,and . 1%) * (4) 8-50ml beaker We will be collecting the oxygen in the catalase reaction using the catalase activity measuring apparatus.
Since oxygen is one of the products, it is possible to collect it over time and calculate the rate at which the reaction is progressing. As O2 is evolved in the gas bottle, it passes through the tube into the graduated cylinder displacing the water. The number of mls of oxygen in the graduated cylinder can be recorded at regular intervals and then plotted on graph paper to show the rate of the reaction. (Lab manual) Series of trials the concentration of the catalase will be kept constant. Method
For this series of trials, the concentration of the catalase will be kept constant. You are to choose a catalase concentration which gave a controlled reaction in the previous experiment and use it for this series of trials. Remember that 3% hydrogen peroxide is three times as concentration 1% and should give a more robust response. Beaker i-4 will contain the enzyme concentration that you choose. The temperature will be the same as in the previous experiment. The variable will be the concentration of hydrogen peroxide. (lab manual) Results olg