Enzyme Catalysis

Basic Kinetics Tutorial

Notes on usage of the Kinetics tutorial

The Java program above has three panels.
  • The top depicts a graph of the Enzyme rate vs. [S]. There are two lines on the first graph here:
    • The black one is a reference graph whose Data (Km and Vmax) ALWAYS remain unchanged even as the scale on the graph changes.
    • The RED one is the one whose data that you manipulate with the sliders.
    • A relative scale of the graph is indicated at the top.
  • The two bar graphs on the top right represent formation about the current conditions chosen
    • The panel at top right gives a bar graph representation of the current [S], [P], and enzyme rates as well as
    • the log of the final equilibrium position.
  • The middle panel provides numerical representation of the same data.
    • units for the parameters
    • all concentrations ([S], [P], [E]) are in M/l (Molar)
    • kcat = sec-1
    • enzyme rates (vmax and vo=Rate of [P]) = moles/sec (moles of product produced per sec)
    • Km = Molar
    • kcat/Km = Molar sec
    • Keq is unitless
  • The bottom panel provides some interaction.

  • Sliders on the bottom panel allow you to independently alter the [S], [P], [E], kcat, Km, Vmax, kcat/Km, Keq and the Hill coefficient independently to observe the effects.
  • The Radio buttons on the right allow you to maintain the [P]= 0 or allow [P] to accumulate.

In the latter case you should observe that eventually the ratio of [S] and [P] will come to the same ratio as indicated in the "final equilibrium position" window. This final equilibrium position can be altered by changing the DG of the reaction.

The bar graphs update in at a rate 10 times faster than "real time" this is solely to make the changes in the graph visible and more interesting to watch.

Alter each parameter one at a time. Observe what the changes are in values that are linked as well as what happens to the graph itself.

Notes: the kcat/Km, kcat, Km, Vmax and [E] values are linked computationally observe what happens to each as you alter any of the one of the set.