BIOM20001 Lecture Notes - Lecture 32: Hurler Syndrome, Ldl Receptor, Clathrin
Document Summary
Hurler"s disease - enzyme ( -l-iduronidase) required for breakdown of glycosaminoglycan (gag) chains is defective. Lysosome enlarges and cell dies because it can"t get rid of gag. In severely affected individuals with hurler disease, accumulation of gag causes enlargement of both the liver and spleen (hepatosplenomegaly). The liver may also be enlarged in individuals throughout the spectrum. The large liver does not usually cause liver problems, but it can interfere with eating and breathing. I-cell disease (mucolipidosis ii) - enzyme that adds m6p tag to hydrolytic enzymes is defective. Undigested materials accumulate in lysosomes, damaging the cell and lysosomal enzymes are found in the blood (inactive at ph7. 2). Causes accumulation of molecules in endosome which are not degraded. Endocytosis: transport into the cell from the plasma membrane. Specialized phagocytic cells can ingest large particles, e. g. macrophage. Pinocytic vesicles form from clathrin coated pits in the plasma membrane. Smaller molecules and fluids can be taken up by pinocytosis.
