Changes

==1. What are Omega-6 Fatty Acids?==

==1. What are Omega-6 Fatty Acids?==

Omega-6 fatty acids are a family of polyunsaturated straight-chain hydrocarbons that have a double bond in the sixth carbon-carbon bond (n-6) when counted from the methyl end of the molecule. Linoleic acid contains 18 carbons with double bonds at both the n-6 and n-9 positions (written as 18:2n-6). It undergoes further desaturation by hepatic Δ-6 desaturase to form gamma-linolenic acid (GLA; 18:3n-6), which is elongated and desaturated once more to form arachidonic acid (AA; 20:4n-6).  Linoleic acid (LA) is considered an essential fatty acid in both dogs and cats. Dogs are able to convert adequate amounts of LA to AA to meet requirements at all life-stages<ref>Dunbar BL and Bauer JE. Conversion of essential fatty acids by delta-6 desaturase enzyme in dog liver microsomes. J Nutr 2000;132:1701S-1703S.</ref>, cats however have limited hepatic Δ-6 desaturase enzyme activity<ref name="Sinclair">Sinclair AJ, et al. Essential fatty acid deficiency and evidence for arachidonate synthesis in the cat. Br J Nutr 1981;46:93-93.</ref><ref name="Rivers">Rivers JPW. Essential fatty acids in cats. J Small Anim Prac 1982;23:563-576.</ref><ref>Bauer JE. Fatty acid metabolism in domestic cats (Felis catus) and cheetahs (Acononyx jubatus). Proc Nat Soc 1997;56:1013-1024.</ref> and require a dietary source of AA to meet their metabolic needs. The dietary requirement for LA in cats is lower than dogs because LA is not used as a precursor for synthesis of AA.  

<span style="color:red">Omega-6 fatty acids are a family of polyunsaturated straight-chain hydrocarbons that have a double bond in the sixth carbon-carbon bond (n-6) when counted from the methyl end of the molecule. FIGURE SHOWING METHYL END, OMEGA BOND</span> <span style="color:red">Linoleic acid contains 18 carbons with double bonds at both the n-6 and n-9 positions (written as 18:2n-6). It undergoes further desaturation by hepatic Δ-6 desaturase to form gamma-linolenic acid (GLA; 18:3n-6), which is elongated and desaturated once more to form arachidonic acid (AA; 20:4n-6). SCHEMATIC?</span> Linoleic acid (LA) is considered an essential fatty acid in both dogs and cats. Dogs are able to convert adequate amounts of LA to AA to meet requirements at all life-stages<ref>Dunbar BL and Bauer JE. Conversion of essential fatty acids by delta-6 desaturase enzyme in dog liver microsomes. J Nutr 2000;132:1701S-1703S.</ref>, cats however have limited hepatic Δ-6 desaturase enzyme activity<ref name="Sinclair">Sinclair AJ, et al. Essential fatty acid deficiency and evidence for arachidonate synthesis in the cat. Br J Nutr 1981;46:93-93.</ref><ref name="Rivers">Rivers JPW. Essential fatty acids in cats. J Small Anim Prac 1982;23:563-576.</ref><ref>Bauer JE. Fatty acid metabolism in domestic cats (Felis catus) and cheetahs (Acononyx jubatus). Proc Nat Soc 1997;56:1013-1024.</ref> and require a dietary source of AA to meet their metabolic needs. The dietary requirement for LA in cats is lower than dogs because LA is not used as a precursor for synthesis of AA.

==2. Why are they Important?==

==2. Why are they Important?==