They form what is called an enzyme substrate complex (letter C). This union is brief, and the breaking of the substrate into new compounds (letter E) is nearly instantaneous. In our case, the enzyme is catalase, the substrate is hydrogen peroxide, and the newly formed compounds are oxygen gas and water.
Then, what is the substrate for the enzyme catalase?
In biochemistry, the substrate is a molecule upon which an enzyme acts. Enzymes catalyze chemical reactions involving the substrate(s). In the case of a single substrate, the substrate bonds with the enzyme active site, and an enzyme-substrate complex is formed.
What is the relationship between the catalase and hydrogen peroxide?
Watch each of the potato/hydrogen peroxide mixtures and record what happens. The bubbling reaction you see is the metabolic process of decomposition, described earlier. This reaction is caused by catalase, an enzyme within the potato. You are observing catalase breaking hydrogen peroxide into oxygen and water.