In a Series of Laboratory Experiments, You Discover That Reducing

Multiple Choice

In a series of laboratory experiments, you discover that reducing the pH of an enzymatic reaction reduces the biological activity of the enzyme to zero. When the change in pH is reversed the activity of the enzyme returns to normal. The best explanation for these observations is that at low pH the active site of the enzyme becomes non-functional because of a change in the enzyme's

A) primary structure.
B) secondary structure.
C) primary and secondary structure.
D) tertiary structure.
E) primary and tertiary structure.