A kinetic analysis of the opened bicyclic enzyme cascade is presented.
It includes the time-dependence of the concentrations of the modified
and unmodified forms of the interconvertible enzymes, as well as thei
r fractional modifications, from the onset of the reaction to its comp
letion. The transient phase equations obtained allow the definition of
new regulatory properties. The expressions corresponding to the conce
ntrations and fractional modification in the steady-state are derived
as particular cases of the general transient phase equations. These st
eady-state expressions agree with those obtained by other authors.