In this video lecture, educator describes the Lipid Metabolism. Lipids includes, Neutral fat also known as triglycerides, Phospholipids, Cholesterol, and a few others of less importance. The triglycerides are used in the body mainly to provide energy for the different metabolic processes.
The three fatty acids most commonly present in the triglycerides of the human body are stearic acid which has an 18-carbon chain and is fully saturated with Hydrogen atoms and palmitic acid which has 16 carbon atoms and is fully saturated. Third is oleic acid, which also has an 18-carbon chain but has one double bond in the middle of the chain.
Lipids transport in Body Fluids-Formation of Chylomicrons are absorbed from the intestines into the intestinal lymph. Most triglycerides split into monoglycerides and fatty acids. Resynthesized into new molecules of triglycerides that enter the lymph. Minute, dispersed droplets called chylomicrons diameters are between 0.08 and 0.6 micron. Apoprotein B is adsorbed to the outer surfaces of the chylomicrons increases stability and prevents adherence. 9 %phospholipids, 3 % cholesterol, and 1 % apoprotein B are transported upward and emptied into the circulating venous blood at the juncture of the jugular and subclavian vein.
Chylomicron concentration in the plasma may rise to 1 to 2% of the total plasma. Chylomicrons have a half-life of less than 1 hour. Chylomicrons are removed they pass through the adipose tissue or the liver. Lipoprotein lipase hydrolyzes the phospholipids as well as triglycerides of chylomicrons releasing fatty acids glycerol. The fatty acids diffuse into the fat cells of the adipose tissue and into the liver cells. Fatty acids are again synthesized into triglycerides. Free Fatty Acids are transported in the blood in Combination with Albumin. After chylomicron removal, more than 95 percent of all the lipids in the plasma are in the form of lipoprotein.
Lipids transport in Body Fluids. Removal of chylomicrons is divided into 4 major Classes vLDL: High triglycerides conc and moderate concentrations of both cholesterol and phospholipids, iDL: concentrations of cholesterol and phospholipids are increased, LDL: Derived iDL by who triglycerides removal, high cholesterol and Phospholipid concentrations, HDL: Which contain a high concentration of protein (about 50 per cent) but much smaller concentrations of cholesterol and phospholipids.
Formation and function of lipoproteins is majorly in liver, small amount in intestinal epithelium & transport their lipid components in the blood. About 40 percent of the calories are derived from fats, which is almost equal to the calories derived from carbohydrates.
Hydrolysis of Triglycerides contains hydrolysis into fatty acids and glycerol, both transported in the blood to the active tissues, where they will be oxidized to give energy, Glycerol converted into glycerol-3-phosphate, which enters the glycolytic pathway for glucose breakdown and is thus used for energy and Fatty acids transported to mitochondria through carnitine and degraded into acetyl coenzyme A (acetyl-CoA).