5th February 2024

Physiology

Lipid digestion and absorption are the main steps in lipid metabolism. Once digested and absorbed by the gastrointestinal systems, fatty acids and monoglycerides are recombined back into triglycerides. Triglycerides and cholesterol are packaged into chylomicrons, which travel through the bloodstream to enter adipose and other body tissues. As membrane lipids, triglycerides, and cholesterols are hydrophobic, a transport protein known as lipoprotein allows these lipid molecules to be transported through blood. Lipids are stored in white adipose tissue as triglycerides, formed from a backbone of glycerol + 3 fatty acids.

Once chylomicrons and other lipoproteins travel through tissues, lipoprotein lipase will break down these particles to release triglycerides into fatty acids and glycerol. The main steps of fatty acid catabolism occur in the mitochondria. Long-chain fatty acids must be converted to fatty-acyl-CoA to pass the mitochondrial membrane.