Triacylglycerols are the major storage form of metabolic energy in the body. A typical human body contains more than 100 times as many kilocaries stored as triacylglycerols in adipose tissue than in glycogen storage in the liver and muscle. The breakdown of triacylglycerols for use as energy begins with hydrolysis. The glycerol unit enters energy metabolism as dihydroxyacetone phosphate while the carbons from the fatty acid portions enter as acetyl CoA. The process of fatty acid degradation involves sequential removal of two-carbon units in a series of reactions called β-oxidation.
Conceptual Vocabulary for Fatty Acid Metabolism