Final answer:
In the fed state, triglycerides are taken up by peripheral tissues through the formation of chylomicrons. These chylomicrons are released from the intestine and transported through the lymphatic system into the bloodstream. Lipoprotein lipase, an enzyme present in the capillary walls of peripheral tissues, hydrolyzes the triglycerides of the chylomicrons into free fatty acids and glycerol, allowing them to enter the cells and be used as energy or stored as fat.
Step-by-step explanation:
The free fatty acids and monoacylglycerides that enter the epithelial cells are reincorporated into triglycerides. The triglycerides are mixed with phospholipids and cholesterol, and surrounded with a protein coat. This new complex, called a chylomicron, is a water-soluble lipoprotein. After being processed by the Golgi apparatus, chylomicrons are released from the cell. Too big to pass through the basement membranes of blood capillaries, chylomicrons instead enter the large pores of lacteals. The lacteals come together to form the lymphatic vessels. The chylomicrons are transported in the lymphatic vessels and empty through the thoracic duct into the subclavian vein of the circulatory system. Once in the bloodstream, the enzyme lipoprotein lipase breaks down the triglycerides of the chylomicrons into free fatty acids and glycerol. These breakdown products then pass through capillary walls to be used for energy by cells or stored in adipose tissue as fat. Liver cells combine the remaining chylomicron remnants with proteins, forming lipoproteins that transport cholesterol in the blood.