Why are they called omega-3 fatty acids?

Answer 1

The name "Omega-3" indicates that the first double bond occurs on the third carbon atom from the end of the molecule or last position (i.e. the omega position, the last letter in Greek alphabet)

To find the place of the double bond, you would count to the third carbon atom from the 'end' carbon atom of the alkenoic acid (the unsaturated fatty acid). More complex unsaturated acid names would include, for example,

Omega-3,6,9-Octadecatrienoic acid (linolenic acid)

(see related link to a structural formula diagram of omega or alpha numbering of unsaturated fatty acids)

Answer 2

Fatty acids that cannot be prepared within an organism by any known chemical pathways; and therefore must be obtained from the diet and hence are called essential fatty acids. And the two essential fatty acids are;

1. Alpha linolenic acid (omega 3 fatty acid) and

2. Linoleic acid (omega 6 fatty acid).

Answer 3

Omega-3 fatty acids are named as such because of the location of the first double bond in their chemical structure, which is located at the third carbon atom from the methyl end of the fatty acid chain.