Lucas Goldoni
Bio Honors
Lab Report
The Effect of Enzyme Concentration, pH, and Temperature on the Rate of Reactions

Abstract: In the lab we submerged pieces of potatoes within different concentration of Hydrogen Peroxide solution, then changed the temperature of the enviorment, and finally changed the pH of the enviorment. The potatoes acted as the enzymes and the Hydrogen Peroxide solution acted as the substrate in our experiment. We discovered that the effects on enzymes changing these variables were all different. We observed that as concentration decreased, the time it took for the potato to float increased. As the time the potato is submerged in hot water increased, the time it took for the potato to float increased then decreased. Lastly we observed that upon increasing the amount of time the potato was submerged in the Hydro Chloric Acid (changing the pH) the time it took for the potato to float increased. Background: This lab was used to learn more about chemical reactions and how they occur. A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. The substances being reacted are called the reactants and the new substance made from the reaction is called the product. All living things possess catalysts, or substances within them that speed up chemical reactions and processes. Enzymes are catalytic molecules that speed the rate at which chemical reactions reach equilibrium. In other words they lower the activation energy needed for a reaction to occur. In this experiment, we will discover how enzymes act as catalysts by causing chemical reactions to occur more quickly within living things. Catalase works to speed up the decomposition of hydrogen peroxide into oxygen and water. We will also test how this process is affected by changes in the temperature of the potato. An enzyme has an active site which holds the reactants in a particular way to facilitate the bonding/bond breaking by lowering the activation energy for the forward and the reverse reactions to occur (but not in a proportionate way). This orientation is essential for any sort of reaction to occur since if the particles don’t have the correct orientation when they collide then no reactions will occur. Also a certain amount of energy is needed in order for a reaction to occur which is called activation enrgy. It is the energy of the particles needed for a reaction to occur when the particles collide. Temperature = measure of molecular motion by lowering the activation energy, more molecules will possess enough energy to overcome the activation energy barrier and cause the reaction, Using a potato and hydrogen peroxide, we can observe how enzymes like catalase work to perform decomposition, or the breaking down, of other substances. We hypothesized