What are lysosomes?
Lysosome (derived from the Greek words lysis, meaning "to loosen", and soma, "body") is a membrane-bound cell organelle found in animal cells (they are absent in red blood cells).
They are structurally and chemically spherical vesicles containing hydrolitic enzymes, which are capable of breaking down virtually all kinds of biomolecules, including proteins,nucleic acids, carbohydrates, lipids, and cellular debris.
They are known to contain more than fifty different enzymes which are all active at an acidic environment of about pH 5.
Thus they act as waste disposal system of the cell by digesting unwanted materials in the cytoplasm, both from outside of the cell and obsolete components inside the cell.