ABSTRACT
In the plant kingdom, a multiplicity of fatty acids with different chain lengths and one, two, or more double bonds in cis(Z)- or trans(E)-configuration, and even triple bonds are found. Fatty acids are called polyunsaturated when they have two or more double bonds. A question which was investigated by classical biochemistry with Chlorella cells and slices of developing Ricinus seeds concerns the specificity of the desaturation reactions with respect to the location of double bonds in fatty acids of different chain length. The fatty acid composition of cyanobacteria differs from bacterial patterns which are normally very simple with regard to unsaturation because anaerobically produced vaccenic and palmitoleic acid predominate. Most microsomal preparations are highly heterogenous due to their definition as a membrane fraction sedimenting between about 20,000 and 100,000 x g. In order to resolve such mixtures, separation methods such as free flow electrophoresis, aqueous phase partitioning, and gradient centrifugation are required.
