The lysosomal enzyme does not destroy its own cytoplasm, because of the following reasons
(i) The enzymes are separated from the cytoplasm by the lysosomal membrane.
(ii) The enzymes have the capability of recognising and digest only foreign matter.
(iii) The lysosomal enzymes usually works in acidic medium of pH less than 7 and the medium is more than 7, i.e., around 7.4 or more.