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BIOD 121 FINAL EXAM 2025–2026 | 100+ VERIFIED
QUESTIONS WITH CORRECT ANSWERS &
DETAILED RATIONALES (A+ STUDY GUIDE
1. Which Acceptable Macronutrient Distribution Range (AMDR) correctly
lists the percent of total daily calories recommended for carbohydrates, fats,
and protein for healthy adults?
A. Carbs 20–35%, Fat 45–65%, Protein 10–35%
B. Carbs 45–65%, Fat 20–35%, Protein 10–35%
C. Carbs 10–35%, Fat 20–35%, Protein 45–65%
D. Carbs 30–50%, Fat 20–45%, Protein 5–15%
Answer: B. Carbs 45–65%, Fat 20–35%, Protein 10–35%
Rationale: AMDRs are ranges expressed as percent of total energy intake
intended to reduce chronic disease risk while providing adequate nutrients.
Carbohydrates are the primary energy source and recommended at 45–65%
of kcal; fats should supply roughly 20–35% of kcal (to provide essential
fatty acids and fat-soluble vitamins), and protein 10–35% (to support tissue
maintenance and metabolic needs). Option A swaps carbs and fats (wrong
,2|Page
proportions), C and D present impossible pairings that would either under-
or oversupply macronutrients. Knowing AMDRs helps plan balanced diets
and interpret energy distribution in meal plans.
2. A 70-kg sedentary adult wants to know the recommended minimal daily
protein intake (RDA to prevent deficiency). Which is closest to that RDA
and how many grams would that person need?
A. 0.5 g/kg → 35 g/day
B. 0.8 g/kg → 56 g/day
C. 1.2 g/kg → 84 g/day
D. 1.6 g/kg → 112 g/day
Answer: B. 0.8 g/kg → 56 g/day
Rationale: The Recommended Dietary Allowance (RDA) for protein to
meet the needs of nearly all (97–98%) healthy adults is 0.8 grams per
kilogram of body weight per day. For a 70-kg person: multiply 70 × 0.8 =
56 grams of protein daily. This RDA is framed to prevent deficiency and
does not necessarily represent optimal intake for athletic training or clinical
recovery, where higher intakes (1.2–2.0 g/kg) may be indicated. Options A,
C, and D represent lower-than-recommended (A) or elevated intakes (C, D)
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used in specific circumstances (elderly, athletes, catabolic states) but not the
standard adult RDA. Mayo Clinic Health System
3. Where is the enzyme pepsin produced and what is its primary substrate?
A. Produced in the pancreas; digests carbohydrates
B. Produced in the stomach (chief cells); digests proteins (peptide bonds)
C. Produced by salivary glands; digests lipids
D. Produced in the small intestine (enterocytes); digests nucleic acids
Answer: B. Produced in the stomach (chief cells); digests proteins
(peptide bonds)
Rationale: Pepsinogen is secreted by gastric chief cells and converted to
active pepsin in the acidic environment of the stomach. Pepsin hydrolyzes
peptide bonds, beginning protein digestion into polypeptides and peptides.
The pancreas secretes proteases (e.g., trypsin, chymotrypsin) into the small
intestine to further digest proteins (so A is incorrect). Salivary glands secrete
amylase (carbohydrate digestion) not lipase (so C is incorrect). Enterocytes
absorb nutrients and produce disaccharidases, but nucleic acid digestion
occurs via pancreatic nucleases and brush-border enzymes (D is incorrect).
Understanding where enzymes act helps predict digestion/absorption sites
and clinical consequences (e.g., achlorhydria reduces pepsin activation).
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4. After digestion, which pathway describes how glucose from a mixed meal
reaches the liver?
A. Glucose is absorbed into lymph via chylomicrons and then delivered to
the liver.
B. Glucose absorbed by enterocytes enters the portal blood (portal vein) and
travels directly to the liver.
C. Glucose passes unchanged in feces to the colon where the liver reclaims
it.
D. Glucose is transported intact inside chylomicrons to the systemic
circulation then to the liver.
Answer: B. Glucose absorbed by enterocytes enters the portal blood
(portal vein) and travels directly to the liver.
Rationale: Monosaccharides (glucose, fructose, galactose) are absorbed
across the intestinal epithelium into the portal circulation, which carries
nutrients directly to the liver for first-pass metabolism. Chylomicrons
transport dietary lipids (triglycerides, fat-soluble vitamins) via the lymphatic
system into the systemic circulation — they do not carry glucose (so A and
D are wrong). Option C is false — glucose is efficiently absorbed in the
small intestine; unabsorbed carbohydrates may reach the colon and be
BIOD 121 FINAL EXAM 2025–2026 | 100+ VERIFIED
QUESTIONS WITH CORRECT ANSWERS &
DETAILED RATIONALES (A+ STUDY GUIDE
1. Which Acceptable Macronutrient Distribution Range (AMDR) correctly
lists the percent of total daily calories recommended for carbohydrates, fats,
and protein for healthy adults?
A. Carbs 20–35%, Fat 45–65%, Protein 10–35%
B. Carbs 45–65%, Fat 20–35%, Protein 10–35%
C. Carbs 10–35%, Fat 20–35%, Protein 45–65%
D. Carbs 30–50%, Fat 20–45%, Protein 5–15%
Answer: B. Carbs 45–65%, Fat 20–35%, Protein 10–35%
Rationale: AMDRs are ranges expressed as percent of total energy intake
intended to reduce chronic disease risk while providing adequate nutrients.
Carbohydrates are the primary energy source and recommended at 45–65%
of kcal; fats should supply roughly 20–35% of kcal (to provide essential
fatty acids and fat-soluble vitamins), and protein 10–35% (to support tissue
maintenance and metabolic needs). Option A swaps carbs and fats (wrong
,2|Page
proportions), C and D present impossible pairings that would either under-
or oversupply macronutrients. Knowing AMDRs helps plan balanced diets
and interpret energy distribution in meal plans.
2. A 70-kg sedentary adult wants to know the recommended minimal daily
protein intake (RDA to prevent deficiency). Which is closest to that RDA
and how many grams would that person need?
A. 0.5 g/kg → 35 g/day
B. 0.8 g/kg → 56 g/day
C. 1.2 g/kg → 84 g/day
D. 1.6 g/kg → 112 g/day
Answer: B. 0.8 g/kg → 56 g/day
Rationale: The Recommended Dietary Allowance (RDA) for protein to
meet the needs of nearly all (97–98%) healthy adults is 0.8 grams per
kilogram of body weight per day. For a 70-kg person: multiply 70 × 0.8 =
56 grams of protein daily. This RDA is framed to prevent deficiency and
does not necessarily represent optimal intake for athletic training or clinical
recovery, where higher intakes (1.2–2.0 g/kg) may be indicated. Options A,
C, and D represent lower-than-recommended (A) or elevated intakes (C, D)
,3|Page
used in specific circumstances (elderly, athletes, catabolic states) but not the
standard adult RDA. Mayo Clinic Health System
3. Where is the enzyme pepsin produced and what is its primary substrate?
A. Produced in the pancreas; digests carbohydrates
B. Produced in the stomach (chief cells); digests proteins (peptide bonds)
C. Produced by salivary glands; digests lipids
D. Produced in the small intestine (enterocytes); digests nucleic acids
Answer: B. Produced in the stomach (chief cells); digests proteins
(peptide bonds)
Rationale: Pepsinogen is secreted by gastric chief cells and converted to
active pepsin in the acidic environment of the stomach. Pepsin hydrolyzes
peptide bonds, beginning protein digestion into polypeptides and peptides.
The pancreas secretes proteases (e.g., trypsin, chymotrypsin) into the small
intestine to further digest proteins (so A is incorrect). Salivary glands secrete
amylase (carbohydrate digestion) not lipase (so C is incorrect). Enterocytes
absorb nutrients and produce disaccharidases, but nucleic acid digestion
occurs via pancreatic nucleases and brush-border enzymes (D is incorrect).
Understanding where enzymes act helps predict digestion/absorption sites
and clinical consequences (e.g., achlorhydria reduces pepsin activation).
, 4|Page
4. After digestion, which pathway describes how glucose from a mixed meal
reaches the liver?
A. Glucose is absorbed into lymph via chylomicrons and then delivered to
the liver.
B. Glucose absorbed by enterocytes enters the portal blood (portal vein) and
travels directly to the liver.
C. Glucose passes unchanged in feces to the colon where the liver reclaims
it.
D. Glucose is transported intact inside chylomicrons to the systemic
circulation then to the liver.
Answer: B. Glucose absorbed by enterocytes enters the portal blood
(portal vein) and travels directly to the liver.
Rationale: Monosaccharides (glucose, fructose, galactose) are absorbed
across the intestinal epithelium into the portal circulation, which carries
nutrients directly to the liver for first-pass metabolism. Chylomicrons
transport dietary lipids (triglycerides, fat-soluble vitamins) via the lymphatic
system into the systemic circulation — they do not carry glucose (so A and
D are wrong). Option C is false — glucose is efficiently absorbed in the
small intestine; unabsorbed carbohydrates may reach the colon and be
