Composed mainly of triacylglycerols synthesized in intestinal epithelial cells is
VLDL is synthesized in the liver, particularly after a high carbohydrate meal. It is formed from triacylglycerols that are packaged with cholesterol, apolipoproteins (particularly, apoB-100), and phospholipids, and it is released into the blood, where it acquires apoC-II and apo E.Chylomicrons contain triacylglycerols synthesized from dietary lipid in intestinal epithelial cells. LDL is the cholesterol-rich particle in the blood. Cells take up LDL by LDL binding to the LDL receptor, and the LDL-LDL receptor complex enters the cell via endocytosis. Once inside the cell, the cholesterol is released from cholesterol esters by a lysosomal enzyme and enters the cytoplasm of the cell for further processing. VLDL contains newly synthesized triglyceride and cholesterol produced by the liver. HDL is involved in reverse cholesterol transport, which requires the LCAT reaction. Fatty acids, because they are so hydrophobic, cannot travel freely in the blood and need to be bound to albumin for transport through the circulatory system.
Chylomicrons
VLDL
LDL
HDL
Lipids