The major pathways of lipids (triglyceride and cholesterol) and lipoprotein metabolism

Lipids are considered as organic substances that are relatively insoluble in water while soluble in organic solvents such as alcohol and ether. Unlike carbohydrates, proteins and nucleic acids, lipids are not polymers. Further, lipids are mostly small molecules. More than 90% of the fatty acids found in plasma are in the form of fatty acid esters primarily in the form of triacylglycerol, cholesteryl esters. Lipids can be exogenously from the dietary sources and endogenously mainly from the liver. Due to insolubility of lipids, so the circulation of lipids in the blood is performed by the actions of several transport vehicles such as spherical protein complexes which is known as lipoproteins which is an assembly of lipids with proteins. There are four major types of lipoproteins are participating in transporting lipids in plasma, which are classified based on their density, these includes chylomicrons (CM), very-low-density lipoproteins (VLDL), low-density lipoproteins (LDL), and high-density lipoproteins (HDL). Different types of lipoproteins have a different set of proteins (apoprotein) on their surface, these proteins served as address tags that determine both destination and function of each lipoprotein. In this review, we summarise the pathways and metabolites that involve in lipid and lipoprotein metabolism