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How does catalase speed up the breakdown of hydrogen peroxide?

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dissociation of E–N — reaction mechanism Possible energy diagram for the dissociation of a covalent molecule, E–N, into its ions E⁺ and N⁻ (see text).

Catalase accelerates the decomposition of hydrogen peroxide into water and oxygen by acting as a highly efficient enzyme catalyst. The chemical reaction is represented as:1

$2 H_{2} O_{2} \to 2 H_{2} O + O_{2}$

The enzyme functions by providing an active site where the substrate, hydrogen peroxide, is processed. The rate of this reaction is dependent on the concentrations of both the enzyme and the substrate; as the concentration of hydrogen peroxide increases, the reaction rate rises until the enzyme reaches a point of saturation.12

Because catalase is a protein, its ability to speed up this reaction is strictly dependent on its structural integrity. Factors such as temperature and pH are critical, as they can alter the enzyme's shape and disrupt the active site, thereby reducing its effectiveness. By rapidly breaking down this reactive metabolic by-product, catalase protects cells from oxidative damage.12