Catalase Bi Sample Lab 2



Enzyme Rate of Reaction for Catalase


Life would not be possible without chemical reactions. Chemical reactions are responsible for speeding up the process. A chemical reaction is the process of breaking chemical bonds, forming new bonds or both. The four things that can speed up a chemical reaction is heat, increasing the concentration of reactants, decreasing the concentration of products, and enzymes. Enzyme is a catalase, most the time a protein. Enzymes can control the rate of a reaction, and they also lower activation energy. Enzymes are important in regulating chemical pathways, synthesizing materials needed by cells, releasing energy, and transferring information. Enzymes are involved in digestion, respiration, vision, movement, and thought. There are several things that can affect the function of enzymes like temperature, the pH, and the amount of reactant or product. Simple cells may have as many as 2000 different enzymes, each one catalyzing a different reaction. In this particular lab, your hands act as the enzyme “Catalase”. This enzyme, which is found in your cells, splits hydrogen peroxide, a byproduct made by your cells during cellular respiration,  into water and oxygen.


If  time is increased, then more hydrogen peroxide molecules will be split into water and oxygen


The materials used in this lab were pencils, scissors, envelope, 100 paper hydrogen peroxide molecules, and a watch with a second hand so that a person would be able to keep time for the person tearing the strips.


Take a paper template and cut out 100 hydrogen peroxide molecules. Place the cut out pieces into an envelope. Then have a person act as a catalase and take one piece of the paper molecules out of the envelope at a time and rip it in two and  place the pieces back into the envelope. Have a person hold the envelope person, while another student keeps track of the “tearing” time intervals (10, 20, 30 ,60, and 60 seconds). Count how many molecules are  ripped at the end of each time interval and record this number in your data table. When all time intervals and counts are completed, use the formula below to figure the reaction rate for catalase. Record this rate in  your data table.
M2 – M1 = reaction rate
T2 – T1




Time in seconds


Ripped Hydrogen Peroxide Molecules


Rate of reaction













1. What is an enzyme? What are its functions in living things?
Enzymes are proteins in living systems. Enzymes can control the rate of a reaction, and they lower activation energy.


2. Name several things things that can affect the function of an enzyme?
Temperature, the amount of reactant or product and the pH.

3. Write the chemical equation for the breakdown of hydrogen peroxide by the enzyme catalase.
hydrogen peroxide + catalase yields water + oxygen

4. An enzyme’s efficiency increases with greater substrate concentration, but only up to a point. Why?
all of the active sites of the enzymes become filled with hydrogen peroxide molecules


5. If you were allowed to continue this lab and rip hydrogen peroxide molecules for 240 and 300 seconds. What would happen to the rate of reaction and why would this happen?
It would increase.


6. What can you say about the length of time and the rate of the reaction?
The less time, the more the reaction rate is lowered, and the more time, the more the reaction rate is higher.


7. What would happen to the rate of reaction if you remove the water  and oxygen molecules as soon as they are produced?
It would be faster.


Error Analysis:
All pieces must be returned to the envelope each time interval to correctly simulate what occurs within a cell.


Discussion and Conclusion:
As the time intervals increased, the reaction rate of catalase increased also. In a living cell, more hydrogen peroxide would be broken down by catalase over a longer period of time.