Simulation protocols for GLUT_ss_oi.sedml:

1. As $g_i$ changes from 1 to 50 mM, the steady-state values of $v$ shift from negative (indicating transport from intracellular to extracellular) to positive (indicating transport from extracellular to intracellular).

2. As $K_{Ai}$ increases from 149.65 to 500 per fmol, a negative flow rate (from intracellular to extracellular) is observed when $g_i = g_o$, indicating thermodynamically inconsistent parameters.

3. As $\kappa_{r1}$ increases from 0.36 to 100 fmol/s, the v_max doesn't change, while the MM constant changes.