Determining the 3D Molecular Structure of an Enzyme Allows Researchers

Determining the 3D molecular structure of an enzyme allows researchers to predict several structural features of the enzyme. Select all features that can be investigated, once the 3D structure of an enzyme is available:
I. active site
II. substrate binding site
III. molecular mass
IV. isoelectric point

A) I
B) II
C) I and II
D) III and IV
E) All of the above