Enzyme Kinetics

This page simulates the outcomes of an enzyme kinetics experiment. You can vary the amount of substrate and obtain the initial velocity. Keep in mind that there is some experimental error in the data.

You can download a formatted spread sheet to facilitate your analysis: Spreadsheet. Enter your experimental velocities into column B, the spreadsheet will automatically plot the data and the double reciprocal plot. Enter your guesses for Km and Vmax in the yellow cells (F9,F10) and have solver minimize the value of cell G9. If you need help with solver: Click here.

1. Measure the velocity as a function of [S]. Use substrate concentrations of 0.5, 1, 2, 5, 10, 20 mM.
   Note: You cannot enter [S] values greater than 20 mM.
2. Plot a velocity curve and estimate V_Max and K_M
3. Plot a double reciprocal plot and estimate V_Max and K_M.
4. Determine the V_Max and K_M by directly fitting to the velocity equation using Solver.
5. Compare these to your answers for parts 2, 3, and 4. What type of analysis gives the most accurate characterization of V_Max and K_M?
6. Calculate the turn-over number for this enzyme.

The total amount of enzyme in the reaction is 50 nM. Assume the reaction volume is 1 L.