Cali students....help!!

[lil-baby-tobes]

how or why do trans double bonds generally occur in fatty acids and lipids?

if your at cali and doin this crappy CAB book ..... please help!! tis' question 17!!! x

[blcr11]

All other things being equal, trans isomers are more stable than the corresponding cis isomer. Nature tends toward the most stable arrangement of atoms, and so most (but not all) double bonds in fatty acids are trans. There's a little more to it than that (cis-isomers are more sterically hindered than trans isomers; trans isomers are more easily packed together because they are much less electrically polarized than the corresponding cis isomer, etc.) but in a nutshell that's the reason.