What are Lysosomes?

Small organelles bounded by a single bilayer of lipids and rich in enzymes. Actively involved in metabolic activity such as intracellular digestion and storing of substances. They occur in animal cells, whereas plants have vacuoles that have a similar function and properties in addition to osmotic pressure regulating role. But not found in bacteria except cyano. Bacteria have instead of lysosomes a variety of Hydrolases in space between cell wall and membrane called pericytoplasmic spaceor peiplasmic.