Amylase--Michealis-Menten kinetics?

Forday Wayne Lee fwl at
Sun Nov 5 19:32:01 EST 1995

> Using a simple photometer to detect digestion of iodine-stained 
> starch by salivary amylase, I have gotten a graph that is FAIRLY 
> modeled by the  Michaelis-Menten equation.  But it deviates 
>  Do you have any suggestions as to why?  

The problem could be that you are using a colloid substrate. The kinetics
that you are measuring could be those of mass transfer and not of the

Try doing the experiment at different stirring/shaking speeds and if Vmax
increases with stirring speed, then you are mass transfer limited.

Wayne Lee Forday, Biotechnology Department 
Ngee Ann Polytechnic, Singapore 
fwl at

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