1) A saclike cellular organelle that contains various hydrolytic enzymes.

2) A sac-like compartment inside a cell that has enzymes that can break down cellular components that need to be destroyed.

3) A lysosome is a membrane-bound cell organelle that contains digestive enzymes. Lysosomes are involved with various cell processes. They break down excess or worn-out cell parts. They may be used to destroy invading viruses and bacteria. If the cell is damaged beyond repair, lysosomes can help it to self-destruct in a process called programmed cell death, or apoptosis.