Pepsin is inactivated at pH
a)	Below 3	b)	Below 2	c)	Above 5	d)	Above 3

(c)

Pepsin is inactivated at pH above 5. Pepsin is a proteolytic or protein splitting enzyme. The optimum pH of pepsin is about 2 and the enzyme, therefore, works well in the highly acidic gastric juice, while it is inactivated in the near basic medium.