digestion of lipids

Digestion of Lipids : 

Digestion of Lipids The major dietary lipids are TRIACYL GLRCEROL CHOLESTEROL PHOSPHOLIPIDS

Digestion in Mouth : 

Digestion in Mouth Very little amount of lipid digestion takes place in mouth because of the presence of Lingual lipase. Lingual lipase action continues in stomach also. It acts mainly on short chain Tryglycerides.

Digestion in stomach : 

Digestion in stomach Lipids are emulsified by peristaltic movements Gastric lipase is an important lipid digesting enzyme in stomach. Around 30% digestion of TAG occurs in stomach

Digestion in Intestine : 

Digestion in Intestine Bile Bile Salts Pancreatic Juice – Pancreatic Lipase Co Lipase Cholesterol esterase Phospholipases. All these lipases target primary ester linkage. Emulsification Neutralization of acid

Absorption of lipids : 

Absorption of lipids The end products of lipid digestion are Fatty acids Glycerol 2-Monoacylglycerol 1- Mono acylglycerol Cholesterol Lysophonpholipid

Glycerol Small chain FA Medium chain FA, are directly absorbed from Intestinal lumen into portal vein and are taken to liver : 

Glycerol Small chain FA Medium chain FA, are directly absorbed from Intestinal lumen into portal vein and are taken to liver

Slide 8: 

Other end products like Long chain FA, Cholesterol, Phospholipids, lysophospholipids and 2-mono acylglycerides, are incorporated into molecular aggregates to Mixed Micelle.

Re esterfication inside the Mucosal cell : 

Re esterfication inside the Mucosal cell Free fatty acids combine with mono acylglycerols to form TAG Cholesterol re esterifies to form cholesterol ester Iysophospholipid to phospholipid All these compounds along with apo-A and apo B 48 are incorporated into chylomicrons. These chylomicrons they enter into lacteals or lymph vessels.

Abnormalities of Digestion & Absorption of Lipids : 

Abnormalities of Digestion & Absorption of Lipids STEATORRHEA Excretion of fat in faces more than 6 gms/day This is due to defective Digestion & absorption Usually seen in Chronic Pancreatitis Bile duct obstruction Coeliac diseases, sprue, crohn’s diseases Chyluria Chylotholex