Peroxisome

A peroxisome (IPA: [pɛɜˈɹɒksɪˌsoʊm]) ^[1] is a membrane-bound organelle, a type of microbody, found in the cytoplasm of virtually all eukaryotic cells.^[2][3] Peroxisomes are oxidative organelles. Frequently, molecular oxygen serves as a co-substrate, from which hydrogen peroxide (H₂O₂) is then formed. Peroxisomes owe their name to hydrogen peroxide generating and scavenging activities. They perform key roles in lipid metabolism and the reduction of reactive oxygen species.^[4]

Peroxisomes are involved in the catabolism of very long chain fatty acids, branched chain fatty acids, bile acid intermediates (in the liver), D-amino acids, and polyamines. Peroxisomes also play a role in the biosynthesis of plasmalogens: ether phospholipids critical for the normal function of mammalian brains and lungs.^[5] Peroxisomes contain approximately 10% of the total activity of two enzymes (Glucose-6-phosphate dehydrogenase and 6-Phosphogluconate dehydrogenase) in the pentose phosphate pathway,^[6] which is important for energy metabolism.^[5] It is vigorously debated whether peroxisomes are involved in isoprenoid and cholesterol synthesis in animals.^[5] Other peroxisomal functions include the glyoxylate cycle in germinating seeds ("glyoxysomes"), photorespiration in leaves,^[7] glycolysis in trypanosomes ("glycosomes"), and methanol and amine oxidation and assimilation in some yeasts.