Activity No. 5 Factors that Affect Enzyme Activity Title of the Activity Instructions: 1. All questions and answers should be typewritten. Font: Arial, size 12 and justified paragraph. 2. Questions in black color and your answers in red color. 3. Submit as pdf file. 4. FILE NAME should be: Act5_MCPH30_SURNAME I. Overview As learned from basic chemistry, catalysts alter the energy of activation, Ea, of a chemical reaction. Increasing the Ea decreases the rate of a reaction (negative catalysts) and decreasing the Ea increases the rate of reaction (positive catalysts). Enzymes are complex organic substances produced by an organism to alter the rate of biochemical reactions that take place in the cell. However, unlike inorganic catalysts, enzymes show a high degree of specificity, with each enzyme catalyzing only one kind of reaction for only one kind of substrate. At present, about 2,000 different enzymes have been isolated and characterized. In this experiment, catalase, an enzyme derived from potatoes and which detoxifies peroxides produced in the body from metabolism of amino acids, will be isolated and characterized. All enzymes have a protein component and are affected by physical and chemical factors that denature proteins, e.g., extremes of pH and temperature, presence of metal and non-metal ions, presence of alkaloidal reagents, etc. in this experiment the effect of temperature and pH of catalase is determined. II. Materials and Procedures Containers Potato Hydrogen peroxide Spoon Water Vinegar Salt Dishwashing soap A. Preparation of Catalase enzyme Peel a potato and cut into cube size. In a transparent container, place enough amount of hydrogen peroxide and small amount of dishwashing soap. Put pieces of cube size potato in the container. Note the formation of gas. B. Factors that affect Enzyme Activity B.1 Effect of pH Prepare 3 containers and label each accordingly. Place same pieces of cube size potato in the containers for 2 minutes, and then transfer the potatoes in another 3 containers with hydrogen peroxide and small amount of dishwashing soap. Observe the intensity of formation of gas. Container 1 Container 2 Container 3 1 tbsp of drinking water 1 tbsp of vinegar 2 tsp of salt in 1 tbsp of water B.2 Effect of Temperature Prepare 3 containers and label each accordingly. Place same pieces of cube size potato in the containers for 2 minutes, and then transfer the potatoes in another 3 containers with hydrogen peroxide and small amount of dishwashing soap.. Observe the intensity of formation of gas. Container 1 Room temperature water Hot water Cold water Container 2 Container 3 III. Results and Questions A. Catalase enzyme with Hydrogen peroxide Observation B. Factors that Affect Enzyme Activity B. 1 Effects of pH Observation Container 1 Container 2 Container 3 B.2 Effect of Temperature Observation Container 1 Container 2 Container 3 Questions: 1. 2. 3. 4. Write the equation for the reaction catalyzed by catalase. How does enzyme alter the rate of a chemical reaction? What is the optimum pH and temperature for salivary amylase? What effects do increased pH and increases temperature have on the activity of catalase? Explain your answer a. Increased pH b. Increased temperature 5. What is your conclusion on the activity?
