You characterize a new enzyme’s kinetics. Using a saturating (very high so all E is ES) substrate concentration, you measure the initial rate of the reaction at various enzyme concentrations. Does this data fit the Michaelis Menton model/equation? If not, what may be happening?

E (nM), rate (mM,s)

5, 50
10, 225
15, 500
25, 1500
50, 3600
100, 7200

A. NO, the rate should only vary with substrate concentration, not enzyme concentration. The person collecting the data doesn’t have a clue.

B. No, the activity does not change with increasing enzyme concentration correctly. The enzyme may be only active in a dimer that forms a high concentration.

C. Yes, it obeys the MM equation well.

D. No, the activity does not change with increasing enzyme concentration correctly. The enzyme may be inactive in a dimer that forms at high concentration

E. No, the rate should decrease as you increase the enzyme concentration. This reaction is not enzyme catalyzed.