Table 2.

Steady-state rates and free energy dissipation for a minimal model of facilitated diffusion. The free energy dissipation at each step is given by the respective rate isotherm, while that for the overall reaction is given by the overall probability isotherm, the thermodynamic alter ego of the van't Hoff isotherm.

rates
reactionstepforwardbackwardΔGdiss (kJ mol−1)
1A1+E1k1k1E1Ar1=k1[A]1[E1]r1=k1[E1A]RTln (r1/r1)
2E1Ak2k2E2Ar2=k2[E1A]r2=k2[E2A]RTln (r2/r2)
3E2Ak3k3A2+E2r3=k3[E2A]r3=k3[A]2[E2]RTln (r3/r3)
4E2k4k4E1r4=k4[E2]r4=k4[E1]RTln (r4/r4)
overallA1A2[r1r2r3r4/denominator][r1r2r3r4/denominator]RTln ([A]1/[A]2)
where, following Boudart [1], the denominator=r2r3r4+r1r3r4+r1r2r4+r1r2r3.