The insolubility of fatty acids in cellular environments requires that spec
ific trafficking mechanisms be da,eloped to vectorally orient and deliver l
ipids for cellular needs. The roles of putative membrane bound fatty acid t
ransporters and soluble carrier proteins are discussed in terms of mechanis
ms of fatty acid trafficking. The numerous roles for fatty acids as an ener
gy source, as structural elements for membrane synthesis, as bioregulators
and as prohormones with the Potential to regulate gene expression, are disc
ussed in terms of the necessity to regulate their intracellular location an
d concentration.