Here's how it works:

* Catalase is an enzyme that breaks down hydrogen peroxide into water (H₂O) and oxygen (O₂).

* When hydrogen peroxide is added to a sample containing catalase, the enzyme will catalyze the breakdown of the hydrogen peroxide, producing bubbles of oxygen gas.

* The presence of bubbles indicates the presence of catalase.

Procedure:

1. Place a small amount of the sample (e.g., a piece of potato, a drop of blood) in a test tube.

2. Add a few drops of hydrogen peroxide to the sample.

3. Observe for the formation of bubbles. If bubbles appear, it indicates the presence of catalase.

Note:

* The reaction can be accelerated by using a slightly warmed hydrogen peroxide solution.

* Other factors that can affect the reaction rate include pH and temperature.