FREEBIE! Catalase - An Enzyme Common to Both Plants and Animals

Click picture for FREE download

Great Lab Activity!

Concepts covered:

1.  Enzymes speed up the rate of biological chemical reactions.

2.  The same enzymes are found in both plant and animal cells.

3.  The enzyme catalase is compared to the catalyst manganese dioxide.

4.  Enzymes carry out their functions more efficiently than catalysts.

5.  Enzymes can be denatured by excessive heat.

Introduction:  Catalase is an enzyme that is commonly found in plant and animal tissues.  The function of the enzyme catalase is to break down the chemical hydrogen peroxide inside living cells.  Hydrogen peroxide (H₂O₂) is a highly active chemical, often used for bleaching.  

Within cells, hydrogen peroxide is thought to be formed continually as an end product of biochemical reactions such as cellular respiration.  Because it is toxic, or poisonous, it would soon kill the cell if it were not removed or broken down immediately.   Therefore, the catalase found in living cells protects the cell by breaking down or digesting this poisonous hydrogen peroxide into water and oxygen. 

Students will compare the action of
enzymes found in living cells to the action
 of the catalyst, manganese dioxide.

Manganese dioxide is a catalyst.  Catalysts are similar to enzymes in that they speed up chemical reactions, but they are not specific for just one reaction.  

Materials needed:

    Fresh plant and animal tissue                     Test tubes and racks

    Boiled animal tissues                                  Manganese dioxide

    3% hydrogen peroxide solution                  Sand

    Mortar and pestle

Catalase is an enzyme that is found in all eukaryotic cells.  This lab will work using any fresh and living tissue.  I always use liver as a source of animal cells that contain catalase, and potatoes as a source of plant cells that contain catalase.  I purchase the liver frozen at the grocery store.  When thawed, it works perfect!  Often I will also use a yeast solution to show that fungal cells contain the same enzyme.

Students will learn that heat
 denatures enzymes.  In the boiled liver
to the right in the photo, there
will be no reaction between
catalase and hydrogen peroxide.

Students will learn that heat
does not affect
the functioning of catalysts.
Catalysts are
not denatured by heat.

What reaction will students see as catalase breaks down the hydrogen peroxide?

As you can imagine, students absolutely love this lab!!

Catalase: An Enzyme Common to Both Plants and Animals

Also related:

Lab: How Do Living Cells Deal With Changes in pH?

Lab: The Effect of the Enzyme Amylase on Starch