Question

What is the long chain? Where are they foud? And what are their Functions?​

Answer 1

Answer:

A Structure, Properties, and Assay of Long Chain Fatty Acids

Long chain fatty acids (LCFA), frequently called free fatty acids or nonesterified fatty acids, are straight chain fatty acids containing twelve or more carbon atoms. Because LCFA are usually synthesized in animals or plants from acetyl-CoA and are then degraded two carbons at a time via β-oxidation in animals, the LCFA found most commonly in animals have an even number of carbon atoms. LCFA having carbon chain lengths of 16 and 18 constitute the greatest bulk of fatty acids in animal tissues and most animal diets. The saturated 16-carbon LCFA is palmitic acid, and the saturated 18-carbon LCFA is stearic acid. Unsaturated 18-carbon LCFA are common, with double bonds occurring at C9—C10 (oleic acid); at C9—C10 and C12—C13 (linoleic acid); and at C9—C10, C12—C13, and C15—C16 (linolenic acid). The double bonds found in fatty acids in nature are mostly of the cis configuration. Ruminant fat contains more trans-LCFA than that of nonruminants because rumen microbes isomerize some plant cis-LCFA to trans isomers. Unsaturated LCFA have a lower melting point than saturated LCFA with the same number of carbons and are more susceptible to spontaneous oxidation (Gurr et al., 2002). The 20-carbon polyunsaturated fatty acids, arachidonic acid (double bonds at C5—C6, C8—C9, C11—C12, C14—C15) and eicosapentaenoic acid (also called timnodonic acid), which is arachidonic acid with an additional double bond at C17—C18, are the precursors of the eicosanoids (prostaglandins, leukotrienes, thromboxanes).

Long chain fatty acids are relatively insoluble in water at physiological pH. They dissolve readily in highly alkaline solutions, forming soaps. LCFA are amphiphilic, being quite polar (hydrophilic) at their carboxyl end and quite nonpolar (hydrophobic) at the methyl end. All LCFA must bind to proteins in order to be transported for any significant distance, and albumin is the primary transport protein in plasma (Gurr et al., 2002).