An enzymatic reaction has a Vmax of 20 min. At a substrate concentration of 50 M. the velocity of the reaction is 20 min". Which of the following is most likely true? the K of the reaction is much less than 50 M the Kin of the reaction is much greater than 50 M O the Km of the reaction is equal to 50 M the Ke of the reaction is equal to 25 M O cannot be determined from the information given