Using the Prasinophycean algae Platymonas, Heteromastix, Pedinomonas, and Pyramimonas, subcellular distribution of the enzymes of glycolate metabolism and beta-oxidation pathway have been studied. Glycolate dehydrogenase, hydroxypyruvate reductase, and glutamate-glyoxylate aminotransferase are located in the mitochondria. In addition, the mitochondria of all four species contain acyl-coenzyme A (CoA) dehydrogenase, enoyl-CoA hydratase, and thiolase. In Platymonas, Heteromastix, and Pedinomonas, organelles with the characteristic structure of peroxisomes have been detected which also contain the enzymes acyl-CoA oxidase, enoyl-CoA hydratase and thiolase. However, catalase could not be demonstrated in either the peroxisome-like organelles or in the whole cells.