S(t) in michaelis menten kinetics

[lomkes]

how should I define substrate changing with time in michaelis menten kinetics?? I found this : S(t)=S(0)*(1-(vmax*S(0)/Km+S(0))/S(0))^t, where S(0)-initial substrate concentration, but my tutor says it's not right else I tried to solve:

dE/dt = -k1*E*S + ki*ES + k2*ES

dS/dt = -k1*E*S + ki*ES

dES/dt = k1*E*S - ki*ES - k2*ES

dP/dt = k2*ES

 

I solved those in maple, but I get only plots(which seems fine) and no functions.

So my question is what is the formula that I could use to find out how substrate concentration changes in time???

[Greippi]

Do you want to find the RATE of the reaction, or do you want to pick a time and be able to make a guess at the substrate concentration at that time?

 

Would it not just be the standard M-M equation? i.e. plot substrate conc verses time, from which you can find Vmax and Km (maybe easier to do a Lineweaver-burke plot here), then plug the values in to the M-M equation to get v?

[Chembio]

I think you will find a good answer in the Atkins'Physical Chemistry by P.Atkins and Julio De Paula.

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I think you will find a good answer in the Atkins'Physical Chemistry by P.Atkins and Julio De Paula.

Also you can use this link http://en.wikipedia.org/wiki/Michaelis%E2%80%93Menten_kinetics:-)