A type of organelle found in both animal and plant cells, a peroxisome is a membrane-bound cellular organelle that contains mostly enzymes. Peroxisomes perform important functions, including lipid metabolism and chemical detoxification. They also carry out oxidation reactions that break down fatty acids and amino acids.

The enzymes within peroxisomes serve to transfer hydrogen atoms from various molecules to oxygen, producing hydrogen peroxide (H₂O₂). In this way, peroxisomes neutralize poisons like free radicals that enter the body. They produce large amounts of the toxic H₂O₂ in the process but contain enzymes that convert H₂O₂ into water and oxygen.

Key Points

• A peroxisome is a membrane-bound cellular organelle that contains mostly enzymes found in both animal and plant cells.

• Peroxisomes neutralize harmful substances and produce hydrogen peroxide. They also have enzymes that can convert hydrogen peroxide into water and oxygen.

Key Terms

peroxisome: membrane-bound cellular organelle that contains mostly enzymes; important for detoxification

lipid metabolism: is the synthesis and degradation of lipids in cells

detoxification: removal of toxic substances from a living organism

oxidation: the loss of electrons during a reaction by a molecule, atom or ion

free radicals: unstable atoms that can damage cells, causing illness and ageing