Simple Feedback

Feedback Model

Four species, S1, S2, S3, S4 with boundary species held at X0=10 uM (source) and X1=0 uM (sink). 

Initial values for species: S1 = S2 = S3 = S4 = 0 uM.

Flux rate Equations:

• Flux J0 ( X0 -> S1) = (VM1 * (X0 - S1/Keq1))/(1 + X0 + S1 + S4^h)

• J1 (S1 -> S2 ) = (10 * S1 - 2 * S2) / (1 + S1 + S2)

• J2 (S2 -> S3 ) =  (10 * S2 - 2 * S3) / (1 + S2 + S3)

• J3 (S3 -> S4 ) = (10 * S3 - 2 * S4) / (1 + S3 + S4)

• J4 (S4 -> X1) =  (V4 * S4) / (KS4 + S4)  

Parameters that can be varied: Keq1, VM1, h, V4, KS4 and boundary species X0, X1.

Load the model below and then hit the 'Start' button to run the simulation. Adjust the parameter sliders below the plot to see how they affect the feedback loop.