February 15, 2012
Effects of Temperature on Enzymatic Activity
Temperature is a measure of kinetic energy. As this movement increases, collision rate and intensity, and therefore reaction rates, increase. This experiment was conducted to determine if there is a minimum temperature that increase kinetic energy and denature enzymes to slow enzymatic reactions or fail to catalyze them. The experimental results indicate an increase in temperature will increase reaction rates until proteins denature.
Enzymes combine with reactant molecules (substrate) and bind them closely to one another. The three-dimensional shape of the enzyme molecule must be complementary to the shape of the substrate. Catalysts are not used up in the reaction, and do not furnish energy for the reaction. The reaction can proceed rapidly without much activation energy. Most of these reactions are essentially reversible, and the direction in which the reaction goes depends on the concentration of the reactants in relation to the concentration of the products. The rate of these reactions is controlled by biological catalysts of which are the enzymes. Catalase is an enzyme found in most cells and helps decompose hydrogen peroxide into oxygen and water. There is variation of the effects of temperature upon catalase. Catalysts are not used up in the reaction, and do not furnish energy for the reaction. Catalysts merely affect the rate of the reaction by reducing the amount of activation energy required. Catabolic reactions provide raw materials and starting energy for various anabolic activities. Changes in temperature may change the configuration or shape of an enzyme molecule. If this results in altering the "fit" of the enzyme to its substrate, the speed at which the reaction occurs may be slowed or the reaction may not occur at all. Extremes of high temperatures denature enzymes, which stops their action (Sells, 1999).
References: Preszler, R.W., Haas, L. L., Marion, A. L. 2009. Cellular and Organismal Biology Laboratory Manual 8th edition, Hayden-McNeil Publishing, Plymouth, MI. Sells, H (1999). Ehow Family. Retrieved on February 6, 2012 from www.Ehow.com/facts_7776025_temperature-affect-catalase-enzyme-activity.html.