Primary lysosomes to form autophagolysosomes

The degradation of intracellular organelles through the process in which autosomes combine with primary lysosomes to form autophagolysosomes is called

1) Autophagy

  1. Heterophagy

  2. Heteroplasmy

  3. Homophagy

  4. Endocytosis


The primary function of lysosomes is to degrade macromolecules derived from either intracellular organelles (autophagy) or extracellular products (heterophagy). Primary lysosomes are cytoplasmic vacuoles that contain numerous acid hydrolases produced by the Golgi. These vacuoles combine either with vacuoles containing cellular components (autosomes) or with clathrin-coated endocytic vesicles that contain extracellular material (phagosomes). This fusion forms the secondary lysosome (multivesicular body, or phagolysosome) in which the macromolecules are degraded. If the extracellular material is a ligand coupled to a receptor, then the clathrin-coated endocytic vesicle is called a compartment of uncoupling of receptor and ligand (CURL), and the receptors are then recycled to the plasma membrane. The products of the normal lysosomal function are usually reutilized by the cell, but if the material is not digestible (e.g., lipofuscin or hemosiderin), the end result may be production of residual bodies, which may be removed from the cell by exocytosis.