What are primary lysosomes?

Primary lysosomes are homogenous, membrane-bound organelles containing over 50 acid hydrolase enzymes for the purpose of breaking down different types of substances. The pH requirement for hydrolase enzyme activity is under 5 and it is controlled by the membrane ATP-dependent hydrogen ion pump. Primary lysosomes are confined within the Golgi apparatus and are then transported to various locations in the cell after budding. In addition, primary lysosomes fuse together with endosomes to form secondary lysosomes.