Hundreds of chemical reactions take place in your cells. For example, chemical reactions are needed to break down food and release energy, to form new molecules and to produce new cells. All of these reactions require protein molecules called enzymes. An enzyme is a catalyst. A catalyst speeds up a chemical reaction by lowering the energy needed to start the reaction. Catalysts are not used up in a chemical reaction; therefore, catalysts can be used over and over again. Without the help of enzymes, the chemical reactions in your cells would take place too slowly.
A specific enzyme is required for each step of a chemical reaction. Different enzymes are needed for different reactions. The shape of the enzyme enables it to “fit” with a particular substance, called the substrate. The substrate is the reactant of an enzyme catalyzed reaction. In this lab, you will observe the action of catalase, an enzyme found in living things.
Have you ever used hydrogen peroxide to clean a wound? Did you notice any bubbling? When you poured hydrogen peroxide on a wound, you observed the following chemical reaction:
Hydrogen peroxide combined with catalase yields water, oxygen and heat. Catalase breaks down the hydrogen peroxide into water and oxygen (bubbles). You may also feel a little warmth on your skin. Hydrogen peroxide is extremely toxic to living cells; therefore, without catalase, it would damage the cell.
Students will observe the reaction of catalase with hydrogen peroxide. Students will be able to compare the activity of catalase in plant versus animal cells. Students will infer the effect of boiling enzymes.
I designed this lab for use in a Biology classroom. This activity provides students with the basics of chemical reactions and how one particular enzyme works.