where [O 2 ] bg is the concentration of O 2 consumed by processes other than dioxygenation and b is the intercept of the linear regression. An overview of [O 2 ] bg in all experiments is given in Table . an unknown reaction product that is not evident through NO - 2 formation. Accordingly, substrate consumption exceeded detectable product formation in cases listed in Table . Thus, values of f O 2 -uc may underestimate the true extent of O 2 uncoupling as activated oxygen may have reacted in an unaccounted oxygenation reaction.