A small organelle enclosed by a single membrane, and found in most eukaryotic cells. Contains peroxidases and other enzymes involved in a variety of metabolic processes including free radical detoxification, lipid catabolism and biosynthesis, and hydrogen peroxide metabolism. [ https://www.uniprot.org/keywords/KW-0576 http://www.ncbi.nlm.nih.gov/pubmed/9302272 ]