global k1 km1 k2 e0

x0 = [1;0.1;0;0];
% column array of substrate,enzyme,complex,product
% x0 is representative of the variables s0, e0, es0/c0, and p0

t = 0:0.1:100;

k1 = 1;
km1 = 1;
k2 = 5;

K = (km1+k2)/k1;

e0 = x0(2);

[tt,xx] = ode45('catalysis',t,x0);

y0 = x0(1);

[ts,ys] = ode45('michaelis_menten',t,y0);
% defined in catalysis and now using program to produce solution
% ode45 assumes column vector but MATLAB assumes row vector

cs      = e0*ys./(ys+K);
figure
plot(tt,xx),legend('substrate','enzyme','complex','product');
% tt = column vector version of t
% xx = array where #rows is the #time points, #cols=4
% col.1=scons,col.2=e,col.3=c,col.4=p

figure
plot(tt,[xx(:,1),xx(:,3),ys,cs]),legend('substrate','complex','MM substrate','MM complex');

z0 = [x0(1);x0(4)];

(tz,zz)= ode45('michaelis_menten_product');

figure
plot(tz,zz), legend ('substrate','product');