palmitic acid, with 16 carbon atoms (16:0).
This is its most extended conformation, although the hydrocarbon chain is flexible and can bend. Check out the end view:
Oleic acid, with 18 carbon atoms and a double bond betwwen carbons 9 and 10 (18:19).
You may get a
Observe that the two carbons and the four atoms linked to them
lay all in the same
Furthermore, the bond is rigid, does not allow rotation, in contrast to single CH2-CH2
bonds. This is important for the structure of the fatty acid and its properties, such as melting point.