CHAPTER - 9 | Lipid Metabolism
2-monoacylglycerol
mixed micelles 72%
Isomerase 2-monoacylglycerol 1-monoacylglycerol. 28% Lipase act on 1-monoacylglycerol and hydrolyzes about 22% of monoacylglycerol to glycerol and free fatty acids. The remaining 6%monoacylglycerol is absorbed as such. Lipase Absorbed
1-monoacylglycerol 6%
glycerol + Free fatty acids 22%
Cholesterol esters are hydrolyzed by cholesterol esterase to cholesterol and free fatty acids. Phospholipase A2 hydrolyzes phospholipids ester bond on 2 carbon to form lysophospholipid and free fatty acids. cholesterol Cholesterol ester
cholesterol + Free fatty acid esterase
Phospholipase A2 Phospholipids
lyso phospholipids + Free fatty acid
Lysophospholipase act on lysophospholipid and forms glycero phocholine and fatty acid. Lysophospholipase Lyso phospholipids
Glycerophosphocholine +Free fatty acid
Lipid absorption In the proximal part of jejunum 2-monoacyglycerol, free cholesterol, fatty acids, lysophospholipids interact with bile salt micelles and forms mixed micelles. To the brush border membrane mixed micelles carry these products of digestion where they are absorbed through specific transporter present in enterocyte membrane. Bile Lysophospholipids + monoacylglycerol + cholesterol+ Free fatty acids Salts Micelles Specific Mixed micelles Brush border Cytosol of enterocyte Membrane Transporter
2. Write the fate of absorbed lipids in intestine. Explain how they enter circulation? A. In the enterocyte of intestine mono acylglycerol, free fatty acids are converted to triglycerides. Lysophospholipids are converted to phospholipids by esterification. Cholesterol esters are formed from cholesterol and free fatty acids.
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