Saturated fatty acids do not contain any double bonds or other functional groups along the chain. The term "saturated" refers to hydrogen,
in that all carbons (apart from the carboxylic acid [-COOH] group) contain as many hydrogens as possible. In other words, the omega (ω)
end contains 3 hydrogens (CH3-), and each carbon within the chain contains 2 hydrogen atoms.
Saturated fatty acids form straight chains and, as a result, can be packed together very tightly, allowing living organisms to store chemical
energy very densely. The fatty tissues of animals contain large amounts of long-chain saturated fatty acids. In
IUPAC nomenclature, fatty acids
have an [ -oic acid] suffix. In common nomenclature, the suffix is usually -ic.
The shortest descriptions of fatty acids include only the number of carbon atoms and double bonds in them (e.g., C18:0 or 18:0). C18:0 means
that the carbon chain of the fatty acid consists of 18 carbon atoms, and there are no (zero) double bonds in it, whereas C18:1 describes an
18-carbon chain with one double bond in it. Each double bond can be in either a cis- or trans- conformation and in a different position with
respect to the ends of the fatty acid; therefore, not all C18:1s, for example, are identical. If there is one or more double bonds in the fatty
acid, it is no longer considered saturated, rather mono- or polyunsaturated.
References
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