Lipid metabolism is the synthesis and degradation of lipids in cells and organisms for energy. Our body use special proteins which were called lipoproteins to move hydrophobic lipid molecules, through the aqueous blood and tissue lymph environment. Lipoprotein particles are defined by their complement of associated Apo (apolipoproteins) and their content of CHOL (cholesterol), TG (triglyceride) and phospholipid that each particle carries. These transport lipoproteins are categorized by their density levels and subdivides them into 4 major classes: HDL (high density lipoprotein), LDL (low density lipoprotein), VLDL (very low density lipoprotein), and chylomicrons. Lipid metabolism disorders are critically involved in Gaucher's Disease (Type I, Type II, and Type III), Neimann-Pick Disease, Tay-Sachs Disease, and Fabry's Disease.