Which of these best describes the type of digestion proteins undergo in the mouth and the stomach, respectively?

• A. Mouth: mechanical only; Stomach: chemical denaturation and enzymatic proteolysis.
• B. Mouth: enzymatic proteolysis by salivary peptidases; Stomach: mechanical agitation only.
• C. Mouth: emulsification by saliva; Stomach: absorption of intact proteins without digestion.
• D. Mouth: chemical hydrolysis by lingual lipase; Stomach: neutral pH enzymatic cleavage by amylases.

Answer: (A)