Answer to Question #16464 in Biochemistry for Kara Hernandez

Question #16464

I am trying to understand why my book and teacher says linoleNic acid is NOT an essential fatty acid, but DHA is. Everywhere i have read else where says that linoleic AND linoleNic are essential. Please help me understand this. The book provides no explaination. Here is a link to the book and page which states this
http://books.google.com/books?id=40Phuq2tw8UC&pg=PA105&lpg=PA105&dq=biochemistry+for+the+pharmaceutical+sciences+says+linolenic+acid+is+NOT+essential&source=bl&ots=6hgQi94OjJ&sig=tOLrFsu5TjOKJc-xVdHf5T42OP4&hl=en&sa=X&ei=0gB6UKGaKIXA9gTVmIHwCQ&ved=0CC4Q6AEwAA#v=onepage&q=biochemistry%20for%20the%20pharmaceutical%20sciences%20says%20linolenic%20acid%20is%20NOT%20essential&f=false

Expert's answer

It is because of fact that in the presence of the essential linolic acid in the
organism the linoleNic acid could be synthesised.