Triglyeriden

Triglyeriden, in English commonly referred to as triglycerides, are a class of neutral lipids that store chemical energy in many organisms. They consist of a glycerol backbone esterified with three fatty acids and are hydrophobic, existing mainly as large droplets within cells.

Chemically, a triglyceride is formed when three fatty acid molecules attach to the three hydroxyl groups of glycerol via ester bonds. The fatty acid chains vary in length and degree of saturation, ranging from short to very long chains and from fully saturated to polyunsaturated. This diversity influences the physical properties of the triglycerides and their biological roles.

Biological role and transport are central to triglycerides. In animals, they are the primary energy reserve stored in adipocytes as lipid droplets. When energy is needed, enzymes release fatty acids that tissues can oxidize for fuel. Dietary triglycerides are absorbed in the intestine, reassembled into triglycerides in intestinal cells, and packaged into lipoproteins for transport in the bloodstream. Chylomicrons carry dietary triglycerides from the gut, while the liver packages triglycerides into very low-density lipoproteins (VLDL) for distribution to tissues.

Metabolism and regulation are linked to overall lipid homeostasis. Triglycerides are cleaved by pancreatic lipase during digestion, forming free fatty acids and monoglycerides that are taken up by enterocytes and re-esterified into triglycerides. Elevated plasma triglyceride levels are associated with metabolic and cardiovascular disorders, but triglycerides also reflect recent dietary intake and metabolic state.

In summary, triglycerides are esterified fatty acids linked to glycerol, serving as a major energy reservoir and a key component of lipid transport and metabolism in many organisms.