Answer: Lysosomes.
Lysosomes are the specialized membrane-bound cell organelles present in almost all eukaryotic cells. The lysosomal membrane keeps the acidic (pH 5) compartment of lysosomes segregated from the cytoplasm. Lysosomes play a crucial role in the degradation of waste material and debris inside the cell.
This is accomplished by the action of hydrolytic enzymes also called as acid hydrolases. These enzymes are only active in the acidic medium which is maintained in the lysosomes by proton pumps.
Lysosomes are also called as 'suicide bags' as they clear off the waste material.