(*Pulsed substrate input and MM-response
	x[t]:substrate
 y[t]:free enzyme
z[t]:product
TT:Total enzyme
*)	
ClearAll["Global`*"];
k01=1;k11=1;k20=1;TT=10;Cx=1;Tf=5;T0=Tf/5

x[t]=Cx*Sqrt[100/Pi] Exp[-100 (t-T0)^2];
solution=NDSolve[{y'[t]==-k01*x[t]*y[t]+k11*(TT-y[t])+k20*(TT-y[t]),y[-Tf/5]==TT,z'[t]==k20*(TT-y[t]),z[-Tf/5]==0},{y,z},{t,0,Tf}];
p1=ParametricPlot[Evaluate[{t,x[t]}/.solution],{t,0,Tf},PlotPoints->1000,PlotRange->All,PlotStyle->{RGBColor[1,0,0]}]
p2=ParametricPlot[Evaluate[{t,y[t]}/.solution],{t,0,Tf},PlotPoints->1000,PlotRange->All,PlotStyle->{RGBColor[0,0,0]}]
p3=ParametricPlot[Evaluate[{t,z[t]}/.solution],{t,0,Tf},PlotPoints->1000,PlotRange->All,PlotStyle->{RGBColor[0,0,1]}]
Show[{p1,p2,p3}]

(*
ここにコメント記入



*)