Gut Genius: Advanced Digestive System Trivia

Test your expert knowledge of digestion—from enzymes to microbiomes. Sharp, fun, and brain-tickling questions to challenge curious teens and young adults.

  1. Which enzyme begins protein digestion in the stomach by cleaving peptide bonds at specific amino acids?
    1. Trypsin
    2. Amylase
    3. Pepsin
    4. Lipase
  2. Which structure increases small intestine surface area most and contains capillaries and lacteals for absorption?
    1. Villus
    2. Microvillus
    3. Crypt
    4. Haustra
  3. What hormone, released by I cells in the duodenum, stimulates pancreatic enzyme secretion and gallbladder contraction?
    1. Motilin
    2. Secretin
    3. Gastrin
    4. Cholecystokinin
  4. Which vascular portal system carries nutrient-rich blood from the gastrointestinal tract to the liver?
    1. Systemic vein
    2. Portal sinus
    3. Renal portal
    4. Hepatic portal
  5. What is the primary transport mechanism for monosaccharide entry into enterocytes on the apical membrane?
    1. NaK ATPase
    2. GLUT2
    3. GLUT5
    4. SGLT1
  6. Which condition results from failure of neural crest cell migration causing absence of enteric ganglia in a bowel segment?
    1. Crohn's
    2. Hirschsprung
    3. Ulcerative colitis
    4. Irritable bowel
  7. Which gastric cell type secretes intrinsic factor necessary for vitamin B12 absorption?
    1. Parietal cell
    2. Chief cell
    3. Enterocyte
    4. G cell

Answers and explanations

  1. Question: Which enzyme begins protein digestion in the stomach by cleaving peptide bonds at specific amino acids?
    Answer: Pepsin
    Explanation: Pepsin activates from pepsinogen in acidic stomach juice and cleaves peptide bonds, especially near aromatic residues; trypsin is intestinal, not gastric.
  2. Question: Which structure increases small intestine surface area most and contains capillaries and lacteals for absorption?
    Answer: Villus
    Explanation: Villi are microscopic finger-like projections with capillaries and a lacteal for fat absorption; microvilli are smaller cell surface folds on enterocytes.
  3. Question: What hormone, released by I cells in the duodenum, stimulates pancreatic enzyme secretion and gallbladder contraction?
    Answer: Cholecystokinin
    Explanation: CCK is secreted in response to fats/proteins and triggers pancreatic enzyme release and gallbladder bile ejection; secretin instead stimulates bicarbonate secretion.
  4. Question: Which vascular portal system carries nutrient-rich blood from the gastrointestinal tract to the liver?
    Answer: Hepatic portal
    Explanation: The hepatic portal vein routes absorbed nutrients to the liver for processing and detoxification; the systemic venous system does not first pass through the liver.
  5. Question: What is the primary transport mechanism for monosaccharide entry into enterocytes on the apical membrane?
    Answer: SGLT1
    Explanation: SGLT1 co-transports glucose/galactose with sodium using secondary active transport; GLUT5 handles fructose and passive GLUT2 is basolateral, not apical for glucose.
  6. Question: Which condition results from failure of neural crest cell migration causing absence of enteric ganglia in a bowel segment?
    Answer: Hirschsprung
    Explanation: Hirschsprung disease causes aganglionic megacolon and obstructive constipation due to absent myenteric/Meissner plexuses; IBS is functional, not congenital aganglionosis.
  7. Question: Which gastric cell type secretes intrinsic factor necessary for vitamin B12 absorption?
    Answer: Parietal cell
    Explanation: Parietal (oxyntic) cells secrete intrinsic factor and acid; chief cells produce pepsinogen, so confusing them is a common mistake.