Catalase Lab Sample 1



Enzyme Rate of Reaction for Catalase


Enzymes are an important part of life that regulate chemical reactions with in the body. Enzymes speed up chemical reactions in four different ways, one way is heat, another is increasing the rate of reactants, the third way is decreasing the amount of products and the fourth way is enzymes, which speed up reaction without themselves being used up. Enzymes are also involved in digestion, respiration, reproduction, vision, movement, thought, and also in the productions of other enzymes. Simple cells may have as many as 2000 enzymes with each one catalyzing a different reaction. An enzyme can speed up a reaction making it 10, 000,000,000 times faster. An enzyme is a catalyst. A catalyst is a chemical that reduces the amount of activation interim needed for a reaction. Without enzymes a reaction would take much longer than if it had and enzyme. Enzymes also the control the rate and direction of the reaction.
Without catalysts chemical reactions would take much longer that the average human life expectancy. So that would mean that in 76 years only a couple chemical reactions would take place. Since our bodies have enzymes though hundreds of chemical reactions a day. If our bodies didn’t have catalysts our bodily cells couldn’t function. Some bacteria, however, possess a defense mechanism which can minimize the harm done by the two compounds. These resistant bacteria use two enzymes to catalyze the conversion of hydrogen peroxide  back into diatomic oxygen and water. One of these enzymes is catalase and its presence can be detected by a simple test. The catalase test involves adding hydrogen peroxide to a cultures sample or an agar slant.


The reaction rate of catalase splitting hydrogen peroxide into water and oxygen will increase over time.

The materials used consisted of 100 paper H2O2 molecules, a data table, paper, pencil, calculator, scissors, watch with a second hand, and an enzyme rate of reaction catalase worksheet.

Cut out 100 hydrogen peroxide paper molecules. Double check to make sure there are only 100 paper molecules and place them in an envelope. Then one person will keep track of the time while another person acts as a catalase and tears the paper hydrogen peroxide molecules in half. The torn paper molecules should be returned to the envelope each time. Another person times the person acting as the catalase.  The time intervals in which the paper molecules are to be ripped are 10 seconds, 20 seconds, 30 seconds, and two different 60second periods of time. The results should be  recorded in a data table. The reaction rate for catalase is figured using the formula:
M2 – M1 = Reaction Rate
T2  –  T1





Time in Seconds Ripped H2O2 MoleculesRate of Reaction


1. What is an enzyme? What are its functions in living things?
chemicals that reduce the amount of activation energy needed for reactions to occur; they are proteins in cells that control metabolic reactions


2. Name several things that can affect the functioning of an enzyme.
temperature, pH, and the amount of reactant or product


3. Write the chemical equation for the breakdown of hydrogen peroxide by the enzyme catalase.
H2O2   +   Catalase –>  H2O  + O2


4. An enzyme’s efficiency increases with greater substrate concentration, but only up to a point. Why?
once all active sites are filled, the enzyme’s reaction rate won’t continue increasing


5. If you were allowed to continue this lab and rip hydrogen peroxide molecules for 240 and 300 seconds, what would happen to the reaction rate and why would this happen?
there would be more molecules ripped because of the increased amount of time


6. What can you say about the length of time and the reaction rate?
The more time available, the faster the reaction will occur.


7. What would happen to the reaction rate if you removed the water and oxygen molecules as soon as they were produced?
The rate of reaction would go even faster


Error Analysis:
The counting of the time  may have been off a couple of seconds.


Discussion and Conclusion:
The data shows that the more time there is, the more hydrogen peroxide molecules will be ripped. The catalase in the lab ripped about 6 molecules every 5 seconds. The same thing occurs in a cell as more hydrogen peroxide is produced, catalase speeds up breaking down this waste into water and oxygen.