Lactase Is an Enzyme Composed of a Single Polypeptide That

Multiple Choice

Lactase is an enzyme composed of a single polypeptide that hydrolyzes the disaccharide lactose to produce monosaccharides. The optimal pH for lactase activity is 6. Transfer of lactase to pH 5 results in a substantial decrease in enzyme activity, likely due to the disruption of

A) only the primary structure of the enzyme.
B) the primary and secondary structure of the enzyme.
C) the secondary and tertiary structure of the enzyme.
D) the secondary, tertiary, and quaternary structure of the enzyme.