What is the primary function of High-Density Lipoprotein (HDL) in lipid metabolism?
A Facilitates cholesterol transport from peripheral tissues back to the liver
B Delivers triglycerides to adipose tissue for storage
C Transports dietary cholesterol from intestines to bloodstream
D Carries cholesterol from the liver to peripheral cells
Solution
Correct Answer: Option A
- The primary function of High-Density Lipoprotein (HDL) in lipid metabolism is to facilitate the transport of cholesterol from peripheral tissues back to the liver.
- This process is known as reverse cholesterol transport. HDL acts as a scavenger, collecting excess cholesterol from cells and the arterial walls and delivering it to the liver for excretion or recycling.
- This helps to reduce cholesterol buildup in the arteries, thereby lowering the risk of atherosclerosis and cardiovascular disease.
Option 1 is correct because HDL plays a key role in removing cholesterol from peripheral tissues, which is essential for maintaining lipid balance and preventing plaque formation.
Option 2 describes the function of Very Low-Density Lipoprotein (VLDL) and chylomicrons, which primarily deliver triglycerides to adipose tissue for storage.
Option 3 pertains to Chylomicrons, which transport dietary lipids (including cholesterol) from the intestines to the bloodstream.
Option 4 reflects the function of Low-Density Lipoprotein (LDL), which carries cholesterol from the liver to peripheral cells.
Understanding the roles of different lipoproteins is crucial for grasping lipid metabolism and its implications in diseases.
Reference: Biochemistry, Volume 1, Chapter 12: Lipid Metabolism and Lipoproteins