<prompt> Essential fatty acids are except:Arachidonic acidLinoleic acidPalmitic acidLinolenic acid  <response>: The essential fatty acids are polyunsaturated fatty acids, linoleic acid 18:26 and linolenic acid 18:33. Arachidonic acid 20:46 is derived from dietary linoleic acid and is present primarily in membrane phospholipids. Impoant derivatives of linolenic acid are eicosapentaenoic acid 20:63 and docosahexaenoic acid DHA, 22:63 found in human milk and brain lipids.Palmitic acid is a common saturated fatty acid. Ref : Botham K.M., Mayes P.A. 2011. Chapter 23. Biosynthesis of Fatty Acids Eicosanoids. In D.A. Bender, K.M. Botham, P.A. Weil, P.J. Kennelly, R.K. Murray, V.W. Rodwell Eds, Harpers Illustrated Biochemistry, 29e. 