Membrane lipids triacylglycerols, synthesis

Fatty acids are carried to tissues for use in synthesis of triacylglycerols, phospholipids, and other membrane lipids. The mobilization of fatty acids from triacylglycerol stores and from cholesterol esters depends upon hormone-sensitive lipase (p. 635).53b/ 53c This enzyme is activated by cAMP-dependent phos-... 

Related topics Membrane lipids (El) Triacylglycerols (K4) Fatty acid breakdown (K2) Cholesterol (K5) Fatty acid synthesis (K3)... 

Figure 26.1 PATHWAY INTEGRATION Sources of intermediates in the synthesis of triacylglycerols and phospholipids. Phosphatidate, synthesized from dihydroxyacetone phosphate (DHAP) produced In glycolysis and fatty acids, can be further processed to produce triacylglycerol or phospholipids. Phospholipids and other membrane lipids are continuously produced in all cells.

Fig. 23.3. Major metabolic routes for long-chain fatty acyl Co As. Fatty acids are activated to acyl CoA compounds for degradation in mitochondrial P-oxidation, or incorporation into triacylglycerols or membrane lipids. When P-oxidation is blocked through an inherited enzyme deficiency, or metabolic regulation, excess fatty acids are diverted into tri-acylglycerol synthesis.

CHAPTER 33 / SYNTHESIS OF FATTY ACIDS, TRIACYLGLYCEROLS, AND THE MAJOR MEMBRANE LIPIDS... 

Lacey DJ and Hills MJ (1995) Identification of a low density membrane fraction involved in storage triacylglycerol synthesis. In Plant Lipid Metabolism, Kader J-C and Mazliak P eds pp 482-485 Lacey, D.J. and Hills, M.J. (1996) Heterogeneity of the endoplasmic reticulum with respect to lipid synthesis in developing seeds of Brassica napus L. Plantar In Press... 

Assembly of chylomicrons The enzymes involved in triacylglycerol, cholesterol, and phospholipid synthesis are located in Ihe smooth ER. Assembly of the apolipoproteins and lipid into chylomicrons requires microsomal triacylglycerol transfer protein (see p. 229), which loads apo B-48 with lipid. This occurs during transition from the ER to the Golgi, where the particles are packaged in secretory vesicles. These fuse with the plasma membrane releasing the lipoproteins, which then enter the lymphatic system and, ultimately, the blood. 

Microorganisms, like every other living cell system, produce lipids. All cells are surrounded by membranes that require the synthesis of fatty acids (except in the case of the most ancient of bacteria—the Archaea—where long-chain, branched terpenoid strucmres are used), which are then attached to glycerol 3-phosphate giving rise to the phospholipids and triacylglycerols. This system of fatty acid and lipid... 

Fat Metabolism The liver also plays a central role in synthesis, oxidation, storage, and distribution of lipids. It not only aids in the absorption of fats through the action of the bile salts, but also (1) both synthesizes and oxidizes fatty acids, cholesterol, triacylglycerols, and phospholipids (the major components of cell membranes) (2) synthesizes most of the plasma lipoproteins and (3) converts carbohydrates and proteins into fat. 

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