Dietary triacylglycerols
Dietary TAGs enter the bloodstream in the form of chylomicrons, which is able to interact with the epithelial cell membrane-bound lipoprotein lipase in the lumen of the capillaries of various tissues (adipose tissue in particular).
This lipase hydrolyzes a substantial part (but not all) of the triacylglycerol existing in chylomicrons. The released fatty acids are taken up by the adipocytes, re-esterified with glycerol-3-phosphate (derived from glucose via glycolysis) to form triacylglycerols, and stored as fat droplets within the adipocytes.
After the digestion by lipoprotein lipase, chylomicron remnant leftovers are removed from the circulation by the liver.
Triacylglycerol-containing remnants are hydrolyzed by a lysosomal lipase. The released fatty acids are re-esterified with glycerol-3-phosphate (derived from free glycerol and glucose) to form triacylglycerols. Triacylglycerol is produced from nutritional fat; in