[Campbell Biology P.956] Which of the following statements about the chemical digestion in t... | Practice Question

Which of the following statements about the chemical digestion in the stomach is TRUE?

  • A: Chief cells secrete hydrochloric acid (HCl).
  • B: The pH of gastric juice is slightly alkaline, protecting proteins from denaturation.
  • C: Pepsinogen is the active form of the protein-digesting enzyme, pepsin.
  • D: Hydrochloric acid denatures proteins and activates pepsinogen.

Explanation

Hydrochloric acid HCl in the stomach has two main functions: it denatures proteins, increasing the exposure of their peptide bonds, and it converts the inactive enzyme pepsinogen into its active form, pepsin.