# File quasi_steady_state_approximation.ode
# Figure 2.14 Quasi-steady-state approximation

#assign parameter values
par k0=5, k1=20, km1=12, k2=2

# equations
# original model
a'=k0 - k1*a + km1*b
b'=k1*a - km1*b - k2*b
# approximate model
b_tilde'=k0 - k2*b_tilde
# approximate concentrations
aux a_tilde=(k0+km1*b_tilde)/k1

# initial conditions
init a=8, b=4, b_tilde=7.34375

# final time
@ total=4
# set the plotting window size:
@ xlo=0, xhi=4, ylo=0, yhi=8

# run the simulation in the GUI by selecting (I)nitialconds|(G)o
# plot species b, a_tilde and b_tilde by selecting (G)raphic stuff|(A)dd curve
# and assigning the y-axis

done