Editing Triglyceride (section)

==Biosynthesis==
Triglycerides are tri-[[ester]]s derived from the [[condensation reaction]] of [[glycerol]] with three [[fatty acid]]s. Their formation can be summarised by the following overall equation:

:{{chem2| CH(OH)(CH2OH)2  +  RCOOH  +  R'COOH  +  R"COOH   →   RC(O)OCH2\sCH(OC(O)R')\sCH2C(O)OR"  +  3H2O}}

In nature, the formation of triglycerides is not random; rather, specific fatty acids are selectively condensed with the hydroxyl functional groups of glycerol. Animal fats typically have unsaturated fatty acid residues on carbon atoms 1 and 3. Extreme examples of non-random fats are [[cocoa butter]] (mentioned above) and [[lard]], which contains about 20% triglyceride with [[palmitic acid]] on carbon 2 and [[oleic acid]] on carbons 1 and 3.<ref name=Ullmann/> An early step in the biosynthesis is the formation of the [[glycerol-1-phosphate]]:<ref name=Ullmann/>

:{{chem2| CH(OH)(CH2OH)2  +  H2PO4-  ->  HOCH2\sCH(OH)\sCH2\sOPO3H-  +  H2O}}

The three oxygen atoms in this phosphate ester are differentiated, setting the stage for regiospecific formation of triglycerides, as the [[diol]] reacts selectively with coenzyme-A derivatives of the fatty acids, RC(O)S–CoA:

:{{chem2| HOCH2\sCH(OH)\sCH2\sOPO3H-  +  RC(O)S\sCoA  +  R'C(O)S\sCoA  ->  RC(O)O\sCH2\sCH(\sOC(O)R')\sCH2\sOPO3H-  +  2HS\sCoA}}

The phosphate ester linkage is then hydrolysed to make way for the introduction of a third fatty acid ester:

:{{chem2| RC(O)O\sCH2\sCH(\sOC(O)R')\sCH2\sOPO3H-  +  H2O  ->  RC(O)O\sCH2\sCH(\sOC(O)R')\sCH2OH  +  H2PO4-}}

:{{chem2| RC(O)O\sCH2\sCH(\sOC(O)R')\sCH2OH  +  R"C(O)S\sCoA  ->  RC(O)O\sCH2\sCH(\sOC(O)R')\sCH2\sOC(O)R"  +  HS\sCoA}}