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4.3 Digestion & Absorption — Test 1
Q1. The end product of protein digestion absorbed from the gut is:✓ Amino acids
Q2. Most fat digestion occurs in the:✓ Small intestine (duodenum)
Q3. The lacteals of the intestinal villi receive:✓ Fatty acids and glycerol (as chylomicrons)
Q4. Triglycerides absorbed from the gut travel in lymph as small particles called:✓ Chylomicrons
Q5. Which lipoprotein transports dietary lipids from the intestine toward the liver and tissues?✓ Chylomicrons
Q6. In oral rehydration solution (ORS), glucose is added along with salts because it:✓ Enhances sodium (and hence water) absorption in the intestine
Q7. Water and electrolytes lost in diarrhoea are best replaced by oral rehydration because:✓ Glucose-coupled sodium absorption still works in the gut
Q8. Fructose is absorbed into the intestinal cells (enterocytes) mainly by the transporter:✓ GLUT5 (facilitated diffusion)
Q9. Glucose and galactose are absorbed from the intestinal lumen into enterocytes by:✓ Sodium-dependent co-transport (SGLT1)
Q10. Absorbed monosaccharides leave the enterocyte and enter the blood across the basolateral membrane via:✓ GLUT2
Q11. Intestinal absorption of glucose is impaired by ouabain because ouabain inhibits:✓ The Na⁺/K⁺-ATPase that maintains the sodium gradient
Q12. Di- and tri-peptides are absorbed into enterocytes by a transporter (PepT1) that requires:✓ A proton (H⁺) gradient
Q13. Which one of the following is NOT readily absorbed in the small intestine?✓ Cellulose
4.3 Digestion & Absorption — Test 2
Q14. The microvilli of the intestinal epithelial cells (the brush border) function to:✓ Greatly increase the surface area for absorption
Q15. Vitamin B12 absorption in the small intestine requires:✓ Intrinsic factor (from the stomach)
Q16. In ruminants, mineral absorption takes place largely in the:✓ Small intestine
Q17. The fate of the DNA content of digested food is that it is:✓ Broken down by nucleases into nucleotides and absorbed
Q18. A person who develops diarrhoea, gas and pain after drinking milk most likely has a deficiency of:✓ Lactase
Q19. Iron (Fe2+) is transported out of the enterocyte into the blood (basolateral exit) by:✓ Ferroportin
Q20. Energy balance in the body refers to the relationship between:✓ Energy intake (food) and energy expenditure
Q21. Basal metabolic rate (BMR) is the energy used:✓ At complete rest, awake, in a fasting and thermoneutral state
Q22. Basal metabolic rate (BMR) tends to be lowest when a person is:✓ Asleep
Q23. The relationship between basal metabolic rate and body size in mammals is that smaller animals have a:✓ Higher metabolic rate per unit body mass
Q24. The chief site of nutrient absorption in the human gut is the:✓ Small intestine
Q25. The end products of starch (carbohydrate) digestion that are absorbed are:✓ Monosaccharides such as glucose
Q26. The end products of fat digestion absorbed by the intestine are:✓ Fatty acids and glycerol (mono-glycerides)
4.3 Digestion & Absorption — Test 3
Q27. Absorbed amino acids and monosaccharides leave the gut and travel first to the:✓ Liver (via the hepatic portal vein)
Q28. Bile salts aid fat absorption by forming small aggregates called:✓ Micelles
Q29. Most water in the gut is absorbed in the:✓ Small intestine (with the colon reclaiming the rest)
Q30. The vitamin that must bind intrinsic factor to be absorbed in the ileum is:✓ Vitamin B12
Q31. Fat-soluble vitamins (A, D, E, K) are absorbed:✓ Along with dietary fats, requiring bile salts
Q32. Glucose uptake from the gut lumen into the enterocyte is powered indirectly by:✓ The sodium gradient set by the Na⁺/K⁺ pump
Q33. The intestinal villi increase the surface area for absorption; on each cell, this is further increased by:✓ Microvilli (the brush border)
Q34. The basal metabolic rate (BMR) is influenced most strongly by the hormone:✓ Thyroxine (from the thyroid)
Q35. The energy value (calorific value) is highest per gram for:✓ Fats
Q36. In ruminants, cellulose is digested mainly by:✓ Microbial fermentation in the rumen
Q37. Absorbed dietary fats are released from the intestinal cells into the:✓ Lacteals (lymphatic vessels)
Q38. The hormone that lowers blood glucose after a carbohydrate meal is:✓ Insulin
Q39. Lactose intolerance results from a deficiency of:✓ Lactase at the intestinal brush border
4.3 Digestion & Absorption — Test 4
Q40. Proteins are finally absorbed as amino acids, but many are also taken up as:✓ Di- and tri-peptides (then split inside the cell)
Q41. The total energy expenditure of the body is the sum of BMR, the thermic effect of food and:✓ Energy used in physical activity
Q42. If energy intake exceeds energy expenditure over time, the body will:✓ Store the excess, mainly as fat
Q43. The chief function of the large intestine in relation to nutrients is:✓ Reabsorbing water and electrolytes (little digestion)
Q44. Iron is absorbed best in which form and region?✓ As Fe2+ (ferrous) in the duodenum
Q45. The absorption of glucose and galactose shares the transporter:✓ SGLT1 (sodium-glucose co-transporter)
Q46. The thermic effect of food (specific dynamic action) refers to the:✓ Energy used to digest, absorb and process nutrients
Q47. Oral rehydration therapy works because, even in diarrhoea, the gut can still absorb:✓ Sodium coupled to glucose (pulling water with it)
Q48. Nucleic acids in food are digested by nucleases into nucleotides and then absorbed after being split into:✓ Nitrogenous bases, sugars and phosphate
Q49. The main absorptive region for most nutrients is the:✓ Jejunum and ileum of the small intestine
Q50. A diet very high in fibre (cellulose) is useful because fibre:✓ Adds bulk and aids bowel movement, though it is not digested
Q51. After a fatty meal, the lymph in the lacteals appears milky because it contains:✓ Chylomicrons (fat droplets)
Q52. The basal metabolic rate is measured under conditions that are:✓ Awake, at rest, fasting and thermoneutral