Modeling demo: enzyme kinetics

When using this demo, students can alter the reaction rate, substrate, or enzyme concentrations. The simulation motivates understanding what a basic mechanistic model of enzyme kinetics would consist of.

After running a simulation, the predicted dynamics of the product and substrate are plotted.

The model behind the simulation is:

$latex \frac{dS}{dt} = – r*E*S\\

\frac{dE}{dt} = 0\\

\frac{dP}{dt} = r*ES$

First I ask them a series of questions to motivate the model:

1. How is the amount is substrate changing?
2. When can substrate become product?
3. If you had no enzyme could you get a product?
4. How does the amount of enzyme change over time? I

Then I ask them to write how substrate and products change over time both mathematically and in English. In math language, means “enzyme changing over time”. For example,

means “the change in substrate over time is decreasing with the reaction rate and the amount of substrate and enzyme.”