Consider four enzymes that catalyze the same reaction: S → P. The following table shows the experimentally determined values for Km and Vmax for each of the enzymes. Assume that all four enzymes obey the model for Michaelis-Menten kinetic kinetics. The units for Km are μM. The units for Vmax are μM of S disappearing per minute. You can neglect the units while answering the questions. You need perform absolutely no calculations. You can reason through to the correct answers.

Enzyme Km Vmax

A 10 200

B 30 100

C 70 300

D 90 50

If (S) = 100 μM, which reaction proceeds the slowest: B, C or D?

If (S) = 100 μM, which reaction proceeds at a rate of 176 μM of S disappearing per minute, B, C or D?

If (S) = 30 μM, which reaction proceeds at a rate of 50 μM of S disappearing per minute?

If (S) = 30 μM, which reaction proceeds at a faster rate: A or B?

If (S) = 70 μM, which reaction proceeds at a faster rate: B or C?

If (S) = 90 μM, which reaction proceeds at a slower rate: C or D?

If (S) = 60 μM, which reaction proceeds at a slower rate: A or B?

If (S) = 100 μM, which reaction proceeds at a rate of 33 μM of S disappearing per minute?

If (S) = 100 μM, which reaction proceeds at a rate of 182 μM of S disappearing per minute, A, B or D?

If (S) = 10 μM, which reaction proceeds at a faster rate: A or C?

If (S) = 90 μM, which reaction proceeds the fastest: A, B or D?