Fatty acids (FA) consisting of up to 16 carbons, are synthesized by the well-studied fatty acid synthase (FAS) complex in the cytosol. However, a significant amount of the fatty acids produced by FAS are further elongated into very long chain fatty acids (VLCFA).
VLCFA have been recognized as structural components in a variety of fat molecules such as sphingolipids, glycerophospholipids, triacylglycerols, sterol- and wax-esters. They are found in virtually all cells and are major constituents of the brain, skin and testis. Depending on their chain length and degree of unsaturation, they contribute to membrane fluidity and other chemical properties of the cell.