Hoppsz: linoleátot és linolenátot sem tudunk gyártani !

Linoleate, 18:2(Δ^9,12), and α-linolenate, 18:3(Δ^9,12,15, cannot be synthesized by mammals, but plants can synthesize both. The plant desaturases that introduce double bonds at Δ¹² and Δ¹⁵ positions are located in the endoplasmic reticulum. These enzymes act not on free fatty acids but on a phospholipid, phosphatidylcholine, containing at least one oleate linked to glycerol (Fig. 20-15, p. 656).
Because they are necessary precursors for the synthesis of other products, linoleate and linolenate are essential fatty acids for mammals; they must be obtained from plant material in the diet.

Lehninger-Nelson-Cox: Principles of Biochemistry, 655.o.