The glycosome is a membrane-enclosed organelle that contains the glycolytic enzymes. It is found in a few species of protozoa, most notably in the human pathogenic trypanosomes, which can cause sleeping sickness and Chagas's disease, and Leishmania. The organelle is bounded by a single membrane and contains a dense proteinaceous matrix. It is believed to have evolved from the peroxisome. This has been verified by work done on Leishmania genetics. 
The glycosome is currently being researched as a possible target for drug therapies.