Create a minimal DAE system of a metabolic network where there is an internal conserved quantity. In this case it is the sum of A + B + C = X, where X is the conserved quantity.
Let's define the system as:
D_e <-> D D + A <-> C + E E <-> E_e C <-> B B <-> A
We also have the following boundary conditions
D_e = constant_1 E_e = constant_2
Each of the reactions are catalysed by a reversible michaelis-menten
mechanism, where each reaction is mildly reversible