function dv_dt = met_network(t,v)

global Vmax_msp
global Ca
global Kmsp
global Vmaxpa
global Kmap
global B
global V

global Ns   % initial S
global Np   % initial P
global Na   % initial A


Np = v(1);
Na = v(2);

Vmaxsp = Vmax_msp.*exp(-Na./(V.*Ca));

rate_S_to_P = mich_ment(Vmaxsp,Kmsp,Ns./V);
rate_P_to_A = mich_ment(Vmaxpa,Kmap,Np./V);
rate_loss_A = B.*Na./V;

dv_dt = zeros(2,1);

dv_dt(1) = rate_S_to_P - rate_P_to_A;
dv_dt(2) = rate_P_to_A - rate_loss_A;


function rate = mich_ment(Vmax,Km,C)

rate = Vmax.*C./(C + Km);