Demonstrating the Presence of Catalase in Pig’s Liver

Background Information
Catalase is an enzyme found in many animal tissues such as meat and liver, and many plant tissues, such as stems of seedlings. Catalase is found in the organelle peroxisomes and microbodies in a cell. In industry, it is used to generate oxygen to convert latex to foam rubber. The presence of catalase is important because it can decompose hydrogen peroxide, which is a byproduct of certain cell oxidations and is very toxic. Catalase can eliminate the hydrogen peroxide immediately. It is the fastest-acting enzyme known. Its activity can be demonstrated by dropping a piece of fresh liver into hydrogen peroxide, when rapid evolution of oxygen is observed.

Principles
The evolution of gas should be observed when catalase is placed into hydrogen peroxide. The hydrogen peroxide is decomposed into water.

Procedure

1. Grind 10 gms of fresh pig’s liver in 10 cm3 of distilled water in mortar with a pestle.
2. Filter the liver extract.
3. Dilute the liver filtrate by 100% with distilled water.
4. Add a drop of the filtrate to 5 cm3 of hydrogen peroxide.
5. Observe the evolution of gas.
6. Repeat step 4 with distilled water instead of hydrogen peroxide. Then repeat again with distilled water instead of liver filtrate. These are the controls.
7. If you want to test any other tissues, repeat the procedure with these tissues.

Precautions

1. Hydrogen peroxide solution is corrosive. It may hurt your skin. Wash your fingers if you come in contact with the solution.
2. The extract must be filtered so that the residues will not affect the result.