Sandbox 51: Difference between revisions

==Function==

[[Image:Fatty_acid_breakdown.gif]]<ref>http://www.rpi.edu/dept/bcbp/molbiochem/MBWeb/mb2/part1/lipoprot.htm </ref>

Pancreatic lipase initiates the breakdown of triacylglycerols into 1,2-diacylglycerols and fatty acids.  Lipase is essential to hydrolyzing the very nonpolar triacylglycerols into more polar compounds capable of diffusing across enterocyte membranes, and eventually into circulation.  The digestion of triacylglycerols is a major source of energy storage in metabolism. Consequently, lipase hydrolyzes the ester bonds of the triglycerides.  Lipase, as a digestive enzyme, is soluble in water but the triacylglycerides it hydrolyzes are not.  In the duodenum, bile salts initiate lipase's mechanism by emulsification of the fatty acids.  Bile salts are usually sodium with the deprontated form of digestive acids (mostly derivatives of cholic acid).  Bile salts are stored by the gallbladder and released into the duodenum where they facilitate the formation of micelles.  Bile salts or acids are amphipathic.  Therefore, the hydrophobic region surrounds the fatty acids and the hydrophilic remains on the outside in the process of emulsification, creating smaller micelle molecules.  Micelle formation is essential to maximize the efficiency of lipase by increasing the hydrophilic surface area on which lipase will work <ref>Bowen, R. Absorption of Lipids. 8 August 2007. 3 March 2012. <http://www.vivo.colostate.edu/hbooks/pathphys/digestion/smallgut/absorb_lipids.html>.</ref>.  For the hydrolysis reaction, lipase activity requires bile acids, its coenzyme (colipase), and calcium ions to achieve the correct orientation to hydrolyze the fats <ref>Fundamentals of Biochemistry...</ref>.