Anatomy & Physiology Gastrointestinal #4


Which is a location for protein digestion?


  1. Mouth
    • Rationale:

      The mouth is the location where carbohydrate, not protein, digestion occurs.

  2. Stomach
    • Rationale:

      Protein digestion occurs in the stomach and duodenum where three main enzymes (e.g., chymotrypsin, pepsin, and trypsin) break down food proteins into polypeptides that are then broken down into amino acids.

  3. Esophagus
    • Rationale:

      The esophagus is a long straight hollow structure that starts at the pharynx and ends at the stomach that moves and propels fluids and food along the gastrointestinal (GI) tract via peristalsis. No digestion occurs in this GI structure.

  4. Large intestine
    • Rationale:

      The large intestine is involved in the absorption of water (not proteins) and the removal of any remaining products or by products of digestion not absorbed and used by the body.


Digestion is defined as the process of breaking down food by both enzymatic and mechanical action in the alimentary (i.e., gastrointestinal) canal into substances that can be used by the body via absorption.


Learning Outcomes

Protein digestion occurs in the small intestine and the stomach. Proteins are broken down into amino acids and peptides which can be absorbed for use by the body. Proteins are used by the body to build, digest, oxygenate, regulate, and repair.

Test Taking Tip

Eliminate wrong answers for this question by asking yourself what structures are involved in the digestive process.

Video Rationale