The structures of fatty acids can be represented in a shorthand form consisting of two numbers separated by a colon. The fi rst number is the number of carbons; the second number is the number of double bonds. For example, palmitate would be represented by the shorthand 16:0. For unsaturated fatty acids, the quantity n-x is used, where n is the total number of carbons and x is the last doublebonded carbon counting from the methyl end. Unless indicated otherwise, it is assumed that the double bonds are cis and that one methylene group separates each double bond. For example, oleate would be represented by the shorthand 18:1n-9. Using the shorthand form as a guide, draw the structures of the following fatty acids:

(a) myristate, 14:0

(b) palmitoleate, 16:1n-7

(c) a-linolenate, 18:3 n-3

(d) nervonate, 24:1 n-9