Question regarding rate enhancement! I do not understand how these numbers were

Question

Question regarding rate enhancement! I do not understand how these numbers were calculated. I am required to fill in the rest of the table. My professor posted the answers but did not show how the calculation was done! (the rate enhancement was the numbers given in the answer key)

1. kM: 1.8 (in mM), kcat: 1806 (min ^-1) rate enhancement: 1.67 E 4 (M^-1 s^-1)

2. kM: 4.5 (in mM), kcaT: 17160 (min^-1) rate enhancement: 6.36 E 4 (M^-1 s^-1)

**So I know that the rate enhancement calculation is kcat/km, and that the units of the rate enhancement are different from the units for the given km and kcat. I tried to convert from minutes to seconds and mM to M, then divided, but I CANNOT get the answer given!! PLEASE someone tell me what I am doing incorrectly. THANK YOU!

Explanation / Answer

Ans. It seems that you missed unit conversion step.

#1. Rate enhancement = Kcat / Km        

Given-

            Kcat = 1806 / min = 1806 / 60s = 30.1 s-1

            Km = 1.8 mM = 0.0018 M

Now,

            Rate enhancement = 30.1 s-1 / 0.0018 M = 1.6722 x 104 M-1 s-1

#2. Given-

            Kcat = 17160 / min = 1806 / 60s = 286.0 s-1

            Km = 4.5 mM = 0.0045 M

Now,

            Rate enhancement = 286.0 s-1 / 0.0045 M = 6.3555 x 104 M-1 s-1

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