Alternative definition : KEGG: Lysosomes are membrane-delimited organelles in animal cells serving as the cell's
main digestive compartment to which all sorts of macromolecules are delivered for
degradation. They contain more than 40 hydrolases in an acidic environment (pH of
about 5). After synthesis in the ER, lysosomal enzymes are decorated with mannose-6-phosphate
residues, which are recognized by mannose-6-phosphate receptors in the trans-Golgi
network. They are packaged into clathrin-coated vesicles and are transported to late
endosomes. Substances for digestion are acquired by the lysosomes via a series of
processes including endocytosis, phagocytosis, and autophagy.;