An enzyme-catalyzed reaction has the following reaction rates under different conditions: 17 nmol s-1 (pH 7, 37 °C) , 22 nmol s-1 (pH 7, 25 °C) , 1. 2 nmol s-1 (pH 4, 37 °C) , 10-5 nmol s-1 (pH 10, 37 °C) , 10-5 nmol s-1 (pH 7, 65 °C) , 10-5 nmol s-1 (pH 7, 37 °C, no enzyme) . Based on this information, Which of the following statements are probably true ? (Hint: consider the rate under different conditions compared to the no enzyme condition)
a) The enzyme is more active at 25 °C than it is at 37 °C
b) The active site of the enzyme contains a base that is protonated at pH 7 and below
c) The enzyme is denatured at pH 4
d) The enzyme is denatured at pH 10
e) The enzyme is in its native state at 65 °C