Digestion of nutrients MCQs With Answer

Digestion of nutrients MCQs With Answer — This concise, Student-friendly review is tailored for B.Pharm students studying digestive physiology and clinical pharmacology. It covers enzymatic hydrolysis of carbohydrates, proteins, and lipids; intestinal absorption mechanisms including transporters like SGLT1, GLUT5, and PEPT1; micelle and chylomicron formation; bile salt recycling; and roles of gut microbiota. Emphasis is placed on pH-dependent enzyme activity, absorption kinetics, drug–nutrient interactions, malabsorption syndromes, and implications for pharmacotherapy and clinical nutrition. Use this targeted material to strengthen conceptual understanding and exam readiness. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. Where does salivary amylase primarily begin the digestion of dietary starch?

• Mouth
• Stomach
• Duodenum
• Colon

Correct Answer: Mouth

Q2. Which enzyme is the main pancreatic lipase responsible for triglyceride hydrolysis in the small intestine?

• Lingual lipase
• Gastric lipase
• Pancreatic lipase (colipase-dependent)
• Lecithinase

Correct Answer: Pancreatic lipase (colipase-dependent)

Q3. Which transporter mediates active sodium-dependent glucose uptake across the apical membrane of enterocytes?

• GLUT2
• SGLT1
• GLUT5
• PEPT1

Correct Answer: SGLT1

Q4. Which brush border enzyme hydrolyzes disaccharides like maltose into glucose?

• Maltase
• Sucrase-isomaltase
• Lactase
• Trypsin

Correct Answer: Maltase

Q5. Where are most dietary proteins digested into oligopeptides and amino acids?

• Stomach and small intestine
• Colon
• Esophagus
• Mouth

Correct Answer: Stomach and small intestine

Q6. Which peptide transporter facilitates uptake of di- and tri-peptides into enterocytes?

• SGLT1
• PEPT1
• GLUT2
• ASBT

Correct Answer: PEPT1

Q7. Bile salts aid lipid digestion primarily by:

• Inhibiting lipases
• Forming micelles to solubilize fatty acids and monoglycerides
• Neutralizing pancreatic enzymes
• Stimulating gastric acid secretion

Correct Answer: Forming micelles to solubilize fatty acids and monoglycerides

Q8. Which vitamin requires intrinsic factor for absorption?

• Vitamin C
• Vitamin B12 (cobalamin)
• Vitamin B6
• Vitamin K

Correct Answer: Vitamin B12 (cobalamin)

Q9. Where in the GI tract does most nutrient absorption occur?

• Stomach
• Duodenum and jejunum (small intestine)
• Large intestine
• Oral cavity

Correct Answer: Duodenum and jejunum (small intestine)

Q10. Which enzyme converts pepsinogen to pepsin?

• HCl (acidic environment)
• Trypsin
• Enterokinase
• Amylase

Correct Answer: HCl (acidic environment)

Q11. Which sugar is primarily absorbed via facilitated diffusion by GLUT5?

• Glucose
• Fructose
• Galactose
• Maltose

Correct Answer: Fructose

Q12. Secretin primarily stimulates which pancreatic response?

• Secretion of bicarbonate-rich fluid
• Secretion of digestive enzymes
• Gastric acid secretion
• Bile release from gallbladder

Correct Answer: Secretion of bicarbonate-rich fluid

Q13. Which hormone stimulates pancreatic enzyme secretion and gallbladder contraction?

• Gastrin
• CCK (cholecystokinin)
• Secretin
• Motilin

Correct Answer: CCK (cholecystokinin)

Q14. Which condition is characterized by autoimmune damage to small intestinal villi leading to malabsorption?

• Pancreatitis
• Celiac disease
• Irritable bowel syndrome
• Gastritis

Correct Answer: Celiac disease

Q15. Which lipid transport particle carries dietary triglycerides from enterocytes into lymphatics?

• VLDL
• Chylomicron
• LDL
• HDL

Correct Answer: Chylomicron

Q16. Which enzyme activates trypsinogen to trypsin in the small intestine?

• Enterokinase (enteropeptidase)
• Pepsin
• Amylase
• Lipoprotein lipase

Correct Answer: Enterokinase (enteropeptidase)

Q17. Fat-soluble vitamins (A, D, E, K) are mainly absorbed by:

• Passive diffusion without micelles
• Endocytosis in the stomach
• Incorporation into micelles and chylomicrons
• Active transport via PEPT1

Correct Answer: Incorporation into micelles and chylomicrons

Q18. Which statement about pancreatic exocrine insufficiency is true?

• It enhances fat absorption
• It causes steatorrhea due to lack of digestive enzymes
• It primarily affects vitamin B12 absorption
• It only impairs carbohydrate digestion

Correct Answer: It causes steatorrhea due to lack of digestive enzymes

Q19. Which mineral’s absorption is enhanced by gastric acidity?

• Iron (Fe2+/Fe3+ absorption)
• Calcium absorption unaffected by pH
• Sodium
• Potassium

Correct Answer: Iron (Fe2+/Fe3+ absorption)

Q20. Which mechanism best describes passive diffusion of nutrients across enterocytes?

• Movement down a concentration gradient without carrier proteins
• Sodium-coupled active transport using ATP
• Vesicular transport via endocytosis
• Carrier-mediated facilitated diffusion requiring ATP

Correct Answer: Movement down a concentration gradient without carrier proteins

Q21. Bacterial fermentation in the colon primarily produces which short-chain fatty acids beneficial for colonocytes?

• Acetate, propionate, and butyrate
• Palmitate and stearate
• Linoleate and oleate
• Cholesterol and bile acids

Correct Answer: Acetate, propionate, and butyrate

Q22. Which enzyme cleaves peptide bonds at aromatic amino acids in the small intestine?

• Pepsin
• Chymotrypsin
• Lipase
• Maltase

Correct Answer: Chymotrypsin

Q23. Where is the ileal bile acid transporter located and what is its role?

• Duodenum; secretes bile acids
• Ileum; reabsorbs bile acids for enterohepatic recirculation
• Colon; converts bile acids to secondary bile acids
• Stomach; aids bile acid synthesis

Correct Answer: Ileum; reabsorbs bile acids for enterohepatic recirculation

Q24. Orlistat, an antiobesity drug, reduces fat absorption by inhibiting which enzyme?

• Pancreatic lipase
• Amylase
• Pepsin
• Enterokinase

Correct Answer: Pancreatic lipase

Q25. Which of the following increases with a high-fat meal to facilitate fat digestion?

• Gastrin release only
• CCK release and gallbladder contraction
• Secretin release and decreased bile flow
• Decreased pancreatic enzyme secretion

Correct Answer: CCK release and gallbladder contraction

Q26. Which condition results from inability to digest lactose due to lactase deficiency?

• Fructose intolerance
• Lactose intolerance leading to osmotic diarrhea and bloating
• Celiac disease
• Pancreatic exocrine insufficiency

Correct Answer: Lactose intolerance leading to osmotic diarrhea and bloating

Q27. Enterohepatic circulation of bile acids primarily conserves which component essential for lipid digestion?

• Cholesterol
• Bile salts
• Triglycerides
• Vitamins

Correct Answer: Bile salts

Q28. Which vitamin absorption is primarily passive and unaffected by bile salts?

• Vitamin A
• Vitamin B12
• Vitamin C
• Vitamin K

Correct Answer: Vitamin C

Q29. Which gastric enzyme preferentially initiates lipid digestion in neonates and acidic conditions?

• Pancreatic lipase
• Lingual lipase and gastric lipase
• Chymotrypsin
• Maltase

Correct Answer: Lingual lipase and gastric lipase

Q30. Which transport process is responsible for vitamin B12 uptake in the ileum?

• Passive diffusion across apical membrane
• Intrinsic factor–mediated receptor-mediated endocytosis
• PEPT1-mediated transport
• Facilitated diffusion via GLUT family

Correct Answer: Intrinsic factor–mediated receptor-mediated endocytosis

Q31. A deficiency of intrinsic factor most directly leads to which laboratory finding?

• Hypocalcemia
• Macrocytic anemia due to vitamin B12 deficiency
• Iron overload
• Hypokalemia

Correct Answer: Macrocytic anemia due to vitamin B12 deficiency

Q32. Which pancreatic enzyme is critical for nucleic acid digestion?

• Nuclease (ribonuclease and deoxyribonuclease)
• Protease
• Lipase
• Saccharase

Correct Answer: Nuclease (ribonuclease and deoxyribonuclease)

Q33. What effect do proton pump inhibitors have on nutrient absorption?

• They increase iron and calcium absorption
• They can reduce absorption of iron, calcium, magnesium, and vitamin B12 due to hypochlorhydria
• No effect on nutrient absorption
• They enhance fat-soluble vitamin uptake

Correct Answer: They can reduce absorption of iron, calcium, magnesium, and vitamin B12 due to hypochlorhydria

Q34. Which component is essential for chylomicron assembly inside enterocytes?

• Apolipoprotein B-48 and triglycerides
• Albumin
• Intrinsic factor
• Secretin

Correct Answer: Apolipoprotein B-48 and triglycerides

Q35. Which laboratory test is most useful to detect fat malabsorption (steatorrhea)?

• Serum amylase
• 72-hour fecal fat measurement
• Urine ketone test
• Serum protein electrophoresis

Correct Answer: 72-hour fecal fat measurement

Q36. Which amino acid absorption occurs predominantly via sodium-dependent transporters in the small intestine?

• All amino acids equally by passive diffusion
• Most neutral and basic amino acids via Na+-dependent transporters
• Only essential amino acids via endocytosis
• Peptides only via GLUT transporters

Correct Answer: Most neutral and basic amino acids via Na+-dependent transporters

Q37. Which statement about micelle formation is correct?

• Micelles form in the stomach and carry proteins
• Micelles are formed by bile salts to solubilize fatty acids and monoglycerides for absorption
• Micelles are lipoproteins secreted into blood
• Micelles inhibit vitamin absorption

Correct Answer: Micelles are formed by bile salts to solubilize fatty acids and monoglycerides for absorption

Q38. Which enzyme deficiency can lead to inability to digest disaccharides in the small intestine?

• Pancreatic lipase deficiency
• Brush-border enzyme (e.g., lactase or sucrase) deficiency
• Pepsin deficiency
• HCl overproduction

Correct Answer: Brush-border enzyme (e.g., lactase or sucrase) deficiency

Q39. Which bile acid sequestrant can reduce absorption of fat-soluble vitamins and some drugs?

• Cholestyramine
• Orlistat
• Proton pump inhibitors
• PEG laxative

Correct Answer: Cholestyramine

Q40. The primary energy source for colonocytes derived from bacterial fermentation is:

• Glucose from diet
• Short-chain fatty acids, especially butyrate
• Cholesterol
• Protein fragments

Correct Answer: Short-chain fatty acids, especially butyrate

Q41. Which physiologic factor most directly denatures proteins in the stomach facilitating proteolysis?

• Bile salts
• Low pH (gastric acid)
• Pancreatic bicarbonate
• Bacterial enzymes

Correct Answer: Low pH (gastric acid)

Q42. Which transporter helps basolateral exit of glucose from enterocytes into portal blood after absorption?

• SGLT1
• GLUT2
• PEPT1
• ASBT

Correct Answer: GLUT2

Q43. In malabsorption of vitamin D, which downstream effect is most likely?

• Hypercalcemia
• Hypocalcemia and secondary hyperparathyroidism leading to bone demineralization
• Improved bone density
• Increased clotting factor synthesis

Correct Answer: Hypocalcemia and secondary hyperparathyroidism leading to bone demineralization

Q44. Which of the following best describes enteropeptidase’s clinical relevance?

• It degrades bile salts
• It activates trypsinogen to trypsin, initiating pancreatic zymogen cascade
• It absorbs vitamin B12
• It synthesizes intrinsic factor

Correct Answer: It activates trypsinogen to trypsin, initiating pancreatic zymogen cascade

Q45. Which disorder leads to fat malabsorption due to impaired bile salt delivery to the small intestine?

• Cholestasis or biliary obstruction
• Excessive gastric acid secretion
• Hyperactivity of pancreatic enzymes
• Lactase persistence

Correct Answer: Cholestasis or biliary obstruction

Q46. Which statement best explains passive paracellular absorption in the intestine?

• Transport of solutes through tight junctions down a gradient without carriers
• Transport using ATP-dependent pumps
• Endocytosis of large macromolecules
• Carrier-mediated uptake into lysosomes

Correct Answer: Transport of solutes through tight junctions down a gradient without carriers

Q47. Which nutrient’s absorption can be competitively inhibited by high doses of another mineral (e.g., zinc interfering with copper)?

• Vitamin C absorption inhibited by vitamin E
• Copper absorption inhibited by high zinc intake
• Glucose absorption inhibited by fructose
• Protein absorption inhibited by fat

Correct Answer: Copper absorption inhibited by high zinc intake

Q48. Which clinical test assesses small intestinal bacterial overgrowth (SIBO) by measuring exhaled gases after substrate ingestion?

• Hydrogen breath test
• 72-hour fecal fat test
• Serum albumin level
• Urinalysis

Correct Answer: Hydrogen breath test

Q49. How does pancreatic bicarbonate secretion support digestion?

• Maintains acidic duodenal pH for enzyme activation
• Neutralizes gastric acid to provide optimal pH for pancreatic enzymes
• Promotes bile acid synthesis
• Stimulates gastric motility

Correct Answer: Neutralizes gastric acid to provide optimal pH for pancreatic enzymes

Q50. Which process links digestion to systemic pharmacokinetics by altering oral drug absorption?

• First-pass metabolism only in kidneys
• Gastric emptying, intestinal transit, pH, and interactions with food affecting drug dissolution and absorption
• Drug absorption unaffected by nutrients
• Only hepatic enzyme inhibition

Correct Answer: Gastric emptying, intestinal transit, pH, and interactions with food affecting drug dissolution and absorption

G S Sachin

I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.

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