Peroxisomes are small, membrane­bound cytoplasmic organelles found in both plant and animal cells. Beaufaytt and Berther (1963) called these micro-bodies as peroxisome. These organelles mainly occur in photosynthesising cells of higher plants, algae, liverworts, mosses, ferns and also in fungi. Their number varies from 70-100 per cell. Peroxisomes are rounded bodies whose diameter varies from 0.2-1.5u.

Peroxi­some contains a granular stroma bounded by a unit membrane. A centrally placed opaque area is present in the matrix which is made up of parallel tubules or twisted strands. Animal and plant peroxisomes vary considerably in their enzymatic context. The matrix of peroxisome con­tains peroxide-destroying enzymes (catalases) and peroxide producing en­zymes. They prevent the peroxides from acting on the cellular contents.

Although the exact function of peroxisomes is not known, present evidence suggests that these organelles are associated with glycolate metabolism linked with photorespiration in plants and lipid me­tabolism in animal cells.