Microbodies are membrane-bound organelles specialized as containers for metabolic reactions. Two important types of microbodies are peroxisomes and glyoxysomes. Peroxisomes contain oxidative enzymes that catalyze a class of reactions in which hydrogen peroxide is produced by the transfer of hydrogen from a substrate of oxygen. Perisomes break fats down into smaller molecules that can be used for fuel, and are also used in liver to detoxify compounds harmful to the body, such as alcohol.