These lipid-protein complexes function as a lipid transport system. Because cholesterol and triglycerides are fatty substance , they do not dissolve by themselves solution such as blood.
The ratio of lipids to proteins determines a lipoprotein’s density and its name.
There are four basic types in human blood:
*Chylomicrons
*Very low density lipoproteins
*Low density lipoproteins
*High density lipoprotein
Chylomicrons formed in the gut, transport dietary lipids to the liver and elsewhere in the body. In the liver, chylomicrons are converted to very low density lipoproteins or VLDL, which are the least dense lipoproteins.
VLDL and LDL which are derived from VLDL metabolism, transport fat to the cells.
Low density lipoprotein (LDL) particles act as ferries, taking cholesterol to the parts of the body that need it at any given time.
If too much LDL in the bloodstream, it deposits the cholesterol into the arteries, which can cause blockages and lead to heart attacks.
Because LDL cholesterol plays such a major role in forming atherosclerosis plaque, lowering LDL levels in the blood is an important goal in controlling cholesterol.
High density lipoproteins (LDL) is basically the opposite of LDL. Instead of having a lot of fat, HDL has a lot of protein. HDL picks up cholesterol from cells and transport it to the liver for disposal. HDL act as a vacuum cleaner sucking up as much excess cholesterol as it can.
The liver releases the excess cholesterol with the bile into the small intestine. HDL is stable and doesn’t adhere to artery walls.
Lipoproteins
