triacyloglicerole

Triacylglycerol, commonly called triglyceride, is a glycerol molecule esterified with three fatty acids. It is the most abundant storage form of fatty acids in many organisms and constitutes the primary component of dietary fats as well as body fat in animals and plants. The fatty acid chains vary in length and degree of saturation, giving a wide range of physical properties from oils to fats.

Chemically, triacylglycerol is a neutral lipid formed by three ester bonds linking the hydroxyl groups of glycerol to fatty acyl groups. It is generally hydrophobic and insoluble in water, and is stored in cells as lipid droplets surrounded by a protein coat.

Biological role: TAGs serve as concentrated energy reserves. When energy is needed, adipose tissue triglycerides are hydrolyzed by lipases to release fatty acids for beta-oxidation; glycerol released can be used for glucose synthesis in the liver.

Synthesis and transport: TAGs are formed in tissues by sequential acylation of glycerol-3-phosphate to diacylglycerol and then to triacylglycerol, with the final step catalyzed by DGAT enzymes. Dietary triglycerides are emulsified and absorbed, then assembled into chylomicrons for transport through the bloodstream; in the liver, triglycerides are packaged into VLDL for distribution to tissues.

Clinical relevance: High triglyceride levels in blood (hypertriglyceridemia) are associated with cardiovascular disease and pancreatitis; levels are influenced by diet, insulin sensitivity, and genetic factors.