Lysosomes are vesicles that contain digestive enzymes, which can break down different kinds of macromolecules. Lysosomes are also involved in various cell processes, including secretion, plasma membrane repair, cell signaling and energy metabolism.
Lysosomes are known to contain more than 60 different enzymes and have more than 50 membrane proteins. Mutations in the genes that encode these proteins can cause genetic disorders.
Lysosome-related organelles (LROs) share features with lysosomes. However, they contain specialized cargo and are present in specialized cells. Examples are melanosomes from melanocytes and platelet dense granules. Dysfunction in these organelles is associated with several rare diseases.