Question

When taking an antacid tablet, which of the following enzyme-substrate pairs is most affected by the subsequent change in pH that takes place in the stomach?

• A. Maltase - maltose
• B. Lipase - lipids
• C. Amylase - disaccharides
• D. Pepsin - proteins
• E. Nuclease - nucleic acids

Answer 1

Answer: (D)

Pepsin - proteins

In the stomach, decrease in pH activates pepsinogen into its active form pepsin which breakdown the proteins into amino acids. Pepsinogen is activated only in acidic conditions i.e. when pH is low. If the pH increases, pepsinogen will not be activated into pepsin and digestion of proteins will not occur.

Hence, pH change in stomach will affect the activity of pepsin and thus, the digestion of proteins also.

So, the correct answer is 'Pepsin- proteins'.