Membrane-enclosed organelle found in all eukaryotic cells (see eukaryote ) that is responsible for the cell's digestion of macromolecules, old cell parts, and microorganisms.
Lysosomes contain a wide variety of enzymes that break down macromolecules such as nucleic acids, proteins, and polysaccharides. Many of the products of lysosomal digestion, including amino acids and nucleotides, are recycled back to the cell for use in synthesizing new cellular components.