Catalase is an enzyme catalysing the decomposition of hydrogen peroxide into water and dioxygen.
Structure of catalase
The function of catalase
The oxygen-oxygen bond of hydrogen peroxide is broken by the iron in the heme group, creating a molecule of water and a highly oxidising iron-oxygen bond. This can oxidise a new molecule of hydrogen peroxide giving dioxygen. The enzyme reaction involved is one of the fastest known.
Within the cell, the catalase protects the organism from the harmful oxidising action of hydrogen peroxide.
Catalase is an enzyme with four sub-units. © Vossman, Wikimedia, CC by-sa 3.0