Lysosomes are single membrane bound organelles which are filled with digestive enzymes. Some of their functions are:
1. Digestion of organic wastes produced by metabolic activities of the cell.
2. Carry out autolysis , that is digest worn out organelles within the cell.
3. Protect the cell by digesting any invading germs and bacteria
4. Act as suicidal bags by digesting the entire cellular contents when the cell gets old.
In absence of lysosomes, body will not be able to perform these functions.