What Is a Degradative Reaction?

A degradative reaction breaks down a chemical compound into less complex molecules and is usually accompanied with the release of energy. It is generally represented as AB → A + B where AB is the complex molecule (reactant) and A and B are the smaller molecules (products).

A degradative reaction is one of the different types of chemical reactions. Degradative reactions break down the bonds holding complex molecules to produce smaller molecules. When energy is liberated, the reaction is said to be exergonic.

For example, hydrogen peroxide decomposes into water and oxygen in the presence of the catalase enzyme: 2 H2O2 → 2 H2O + O2. This reaction occurs naturally in the body to break down toxic hydrogen peroxide resulting from metabolic reactions to useful end products, water and oxygen. A similar reaction also occurs during the laboratory preparation of oxygen gas when hydrogen peroxide decomposes in the presence of magnesium (IV) oxide catalyst.

The breakdown of potassium chloride into potassium and chlorine gas is a degradative reaction: 2 KCl (s) → 2 K (s) + Cl2 (g). Using electrolysis, water can be separated into hydrogen gas and oxygen gas through a degradative reaction: 2 H2O → 2 H2 + O2.