The decrease of the more highly unsaturated Czs acids,
with a concomitant increase of the Cls monounsaturate,
suggests that the dehydrogenation reaction is limited at
warmer temperatures. Harris and James have suggested that
temperature controls dehydrogenation by influencing the
amount of 02 available, and that oxygen is the rate-limiting
factor for the reaction (15). As the temperature increases,
oxygen becomes less soluble in the cytoplasm; therefore,
dehydrogenation would not occur to the extent possible
under cooler temperatures. This hypothesis is supported by
the present results.