[starter]

A simple enzymatic reaction involves conversion of A to G.  Given the initial velocity data below, which of the following statements is true?
[A] (?M)          v0 (M/s)
0                         0
25                    7.14 × 10-6
55                    1.57 × 10-5


   a.  KM > 55 ?M 
   b.  KM < 55 ?M 
   c.  KM = 55 ?M 

[Yggdrasil]

Please read the Forum Rules.  You should that show you've at least attempted to answer the problem before we will help you.

Hint:  read up on the Michaelis-Menten equation in a biochemistry text or on wikipedia (http://en.wikipedia.org/wiki/Michaelis_menten).