Role of bile salts-
Ans. is 'c' i.e., Emulsification of lipidso Emulsification is the process which breaks down ingested fats (mainly triglycerides) into smaller droplets so that they can be digested more efficiently. Thus, emulsification mainly helps in digestion of ingested fats.o Micelles formation is the process in which digested fats (FFAs and monoglycerides) are incorporated into much smaller droplets (micelles) so that they can be absorbed more efficiently. Thus, micelles formation helps in absorption of digested fats.o Detergent action of bile salts is necessary for both emulsification and micelles formation.Fat digestiono Ebner's glands on the dorsum of the tongue secrete lingual lipase and the stomach also secretes a lipase (gastric lipase),o However, they are of very little significance in fat digestionQo Fat digestion essentially begins in the duodenum with entry of pancreatic and biliary secretions,o Pancreatic juice contains lipase (pancreatic lipase), the most important enzyme for fat digestion,o The pancreatic lipase digests triglycerides (triacylglycerols) into free fatty acids and 2-monoglycerides (2-monocylglycerols). Pancreatic lipase hydrolyzes 1-and 3-bonds of trigiycerides relative sparing of 2-bonds, so the principal products of its action are free fatty acids and 2-monoglycerides,o Bile-salts help in digestion of fat by emulsification of fat in small intestine by detergent action of bile salts,o The detergent action of bile salts is due to their amphipathic property.o Emulsification increases the surface to volume ratio of the lipid droplets facilitating the action of lipases,o Bile salts also help in formation of micelles.o Micellar formation solubilizes the digested fats and provides a mechanism of their absorption into the enterocytes.o It is interesting to know that on one hand amphipathic property of bile salts helps in digestion and absorption of fats and micelles formation; on the other hand this property also creats a problem by inactivating lipase,o This inactivation of lipase by bile salts is prevented by colipase, a pancreatic enzy me,o Colipase is secreted by pancreas in precursor inactive (zymozen) form as procolipaseQ,o In the intestine, procolipase is converted into active colipase by try psinQ.o After fat digestion, fatty acids and monoglycerides are absorbed in small intestine especially in the jejunumQ and some amount also in ileum.o In side the enterocvte, fatty acids and monoglycerides again form triglycerides.o These triglycerides are incorporated into chylomicrons and transported to lymphatics and from there to blood vessels.
Vit Bl2 absorption
Formation of lipid bilayer
Emulsification of lipids
Fatty acid degradation
Liver and Gall Bladder