Peroxisomes are oval, sac-like organelles that exist in many cells in the body but are most abundant in the liver cells, or hepatocytes. These microscopic cellular structures are so named because they generate hydrogen peroxide in detoxification reactions. The peroxisomes also contain several enzymes to speed up specific cellular reactions. The liver is a primary organ that filters and detoxifies the blood and also produces some digestive enzymes. For these reasons, it contains a large number of peroxisomes.
Alcohol is a common toxin that can be ingested in large quantities. The liver must detoxify the alcohol that is transported through the bloodflow via the hepatic artery from the intestines in order to protect the build-up of alcohol toxins. The peroxisomes in the hepatocytes carry out this function by transferring hydrogen from the ethanol or alcohol molecules to oxygen. The faculty of molecular biology at Florida State University notes that this process is called oxidation. Peroxisomes use the enzyme catalyst peroxidase to facilitate this reaction.
Peroxisomes also contain several other enzymes that facilitate catabolic and anabolic--breaking apart and building--reactions in the body. The site Neuropathology.neoucom.edu notes that one of the most important reactions that the peroxisomes are involved is plasmalogen, or fatty acid synthesis. These are phospholipids, or fats, that are used to make and repair the myelin-protective covering-of the nerves in the body. The peroxisomes also assist in reactions that produce bile acids, cholesterol and other substances in the liver. Bile acids are important in the digestion of fats in the intestines.
Converting Hydrogen Peroxide
Hydrogen peroxide is a common metabolite, or byproduct, of normal reactions that occur throughout the body. However, it is a toxic substance and can cause damage cells and tissues if it is allowed to accumulate. Peroxisomes contain enzymes that convert the hydrogen peroxide into water by removing a single oxygen atom from each molecule of hydrogen peroxide. The harmless water and oxygen are then released safely back into the cells and tissues. Peroxisomes produce an enzyme called catalase for this reaction. The site Neuropathology.neoucom.edu notes that peroxisomal disorders that prevent the breakdown of toxins can cause mental retardation and developmental delays as well as vision and hearing problems due to toxins collecting in the brain and other organs.