Define the Process of Digestion of Fats?
The enzyme in human gut which is responsible for fat digestion is 'lipase', Lipase is secreted by both stomach and pancreas. In stomach, the dietary lipids gel liquidized in presence of heat and gastric contractions. Gastric lipase can only hydrolyze 30% of triglycerides comprising short and medium chain length. Hence, the lipolytic activity of stomach is not important. Only milk fat which contains some short and medium chain fatty acids tends to be hydrolyzed. These short chain fatty acids can then get absorbed through stomach wall into portal vein. Mostly diets have fats which provide long chain fatty acids. Long chain Salty acids entirely depend on emulsification by bile in gut. The pancreatic juice and the bile are secreted together through common bile duct in the duodenum. Bile emulsifies fat into hydrophilic miscelles making lipase more efficacious to act. Pancreatic lipase is specific to hydrolyze p1imm-y ester linkages at carbon position 1 and 3 of glycerol in a triglyceride. After this action, mixture of products is obtained for absorption in jejunum. The products are - glycerol, fatty acids, monoacylglycerol and diacylglycerol. PhosphoLipases act on phospholipids giving glycerol, fatty acid, lysolecithin etc., while cholesteryl esterase acts on esterifies cholesterol to give free cholesterol and fatty acids. Let us now know how after digestion these products are handled for absorption.