Lysosomes are cellular organelles that contain acid hydrolase enzymes that break down waste materials and cellular debris. These are non-specific. They can be described as the stomach of the cell. They are found in animal cells, while their existence in yeasts and plants are disputed. Some biologists say the same roles are performed by lytic vacuoles, while others suggest there is strong evidence that lysosomes are indeed in some plant cells.
Lysosomes digest excess or worn-out organelles, food particles, and engulf viruses or bacteria. The membrane around a lysosome allows the digestive enzymes to work at the 5 pH they require. Lysosomes fuse with vacuoles and dispense their enzymes into the vacuoles, digesting their contents. They are created by the addition of hydrolytic enzymes to early endosomes from the Golgi apparatus. The name lysosome derives from the Greek words lysis, to separate, and soma, body. They are frequently nicknamed "suicide-bags" or "suicide-sacs" by cell biologists due to their autolysis.
Lysosomes were discovered by the Belgian cytologist Christian de Duve in 1949.