Topics:
Animal Physiology, Animal Refresher
Starting Site of Protein Digestion in Non-Ruminants
Digestion of protein in non-ruminants starts from-
- Mouth
- Stomach — Correct Answer
- Duodenum
- None
Explanation:
Correct Answer: Stomach
In non-ruminants, protein digestion begins in the stomach. Gastric HCl denatures proteins and activates pepsin, which cleaves proteins into smaller polypeptides.
Protein Digestion Step-by-Step (Non-Ruminants)
- Stomach: HCl (from parietal cells) denatures proteins + converts pepsinogen → pepsin (Chief cells). Pepsin cleaves proteins → polypeptides.
- Duodenum/Jejunum: Trypsinogen → Trypsin (activated by enterokinase/enteropeptidase from intestinal mucosa). Trypsin activates other proenzymes (chymotrypsinogen, proelastase, procarboxypeptidase).
- Absorption: Amino acids absorbed in duodenum and jejunum (non-ruminants) by active cotransport with Na⁺
Key Enzyme Activations
- Pepsinogen + gastric HCl → Pepsin
- Trypsinogen + Enterokinase → Trypsin (key step)
- Trypsin then activates all other pancreatic proenzymes
Ruminant vs. Non-Ruminant Protein Absorption
- Both: End product = Amino acids
- Ruminants: Absorbed in Ileum
- Non-ruminants: Absorbed in Duodenum & Jejunum
📚 About this Topic — Animal Physiology
This multiple choice question is from Animal Physiology, Animal Refresher. It has 4 options with a detailed explanation of the correct answer. Practice more MCQs from Animal Physiology to strengthen your preparation.
