Vegetative tissue fatty acid synthesis

Biosynthesis of Unsaturated Fatty Acids. In the mammalian tissues, the forma-tion of monoene fatty acids is only possible. Oleic acid is derived from stearic acid, and palmitooleic acid, from palmitic acid. This synthesis is carried out in the endoplasmic reticulum of the liver cells via the monooxigenase oxidation chain. Any other unsaturated fatty acids are not produced in the human organism and must be supplied in vegetable food (plants are capable of generating polyene fatty acids). Polyene fatty acids are essential food factors for mammals. 

Each plant cell manufactures its own fatty acids, since there is no lipid transport in plants. The synthesis begins with acetate which is formed from pyruvate, formed from phosphoglycerate in the Calvin cycle in leaf tissue or via degradation of sugars in seeds or fruits. De novo synthesis of fatty acids takes place in the chloroplasts of vegetative tissues or in plastids of other plant tissues. Acetate is first esterified to the -SH function of coenzyme A (CoA) via an enzyme, acetyl CoA synthetase. Coenzyme A is an adenosine derivative attached to a 4 -phosphopantetheine moiety, a chemical subunit idilch is ubiquitous in the metabolism of fatty acids. 

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