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CHEM 210 BIOCHEMISTRY MODULE 8 EXAM ACTUAL
2026/2027 | Nutrition, Vitamins, Minerals & Metabolic
Disease | Geneva College | Complete Questions & Verified
Answers | Pass Guaranteed - A+ Graded
Section 1: Water-Soluble Vitamins (Q1-15)
Q1. A 58-year-old alcoholic patient presents with nystagmus, ataxia, and confusion.
Biochemical analysis reveals elevated blood pyruvate and lactate. Which vitamin-
derived cofactor is deficient, impairing the conversion of pyruvate to acetyl-CoA?
A. Flavin adenine dinucleotide (FAD) derived from riboflavin
B. Nicotinamide adenine dinucleotide (NAD⁺) derived from niacin
C. Thiamine pyrophosphate (TPP) derived from thiamine [CORRECT]
D. Pyridoxal phosphate (PLP) derived from pyridoxine
Rationale: Thiamine pyrophosphate (TPP) is the essential cofactor for pyruvate
dehydrogenase, which converts pyruvate to acetyl-CoA for entry into the TCA cycle.
Thiamine deficiency in alcoholism causes Wernicke-Korsakoff syndrome and lactic
acidosis due to impaired pyruvate dehydrogenase and α-ketoglutarate
dehydrogenase. FAD, NAD⁺, and PLP are not the primary cofactors for this specific
decarboxylation reaction.
Correct Answer: C
Q2. A 3-year-old child in a refugee camp presents with high-output cardiac failure,
peripheral neuropathy, and bilateral foot drop. The diet consists primarily of polished
white rice. Which vitamin deficiency explains this clinical presentation?
A. Vitamin B12 (cobalamin)
B. Vitamin B1 (thiamine) [CORRECT]
C. Vitamin B3 (niacin)
D. Vitamin B6 (pyridoxine)
Rationale: This presentation of high-output cardiac failure (wet beriberi) and
peripheral neuropathy (dry beriberi) is classic for thiamine deficiency. Polished rice
,2
lacks thiamine-rich bran. Niacin deficiency causes pellagra (dermatitis, diarrhea,
dementia), B12 deficiency causes megaloblastic anemia and neurological
degeneration, and B6 deficiency causes seborrheic dermatitis and microcytic anemia.
Correct Answer: B
Q3. A patient with chronic alcoholism and malnutrition develops cheilosis, angular
stomatitis, and a normocytic anemia. Which cofactor pair is most likely deficient,
impairing both the electron transport chain and glutathione reductase activity?
A. Thiamine pyrophosphate (TPP)
B. Flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN) [CORRECT]
C. Coenzyme A (CoA)
D. Tetrahydrofolate (THF)
Rationale: Riboflavin (vitamin B2) is the precursor of FAD and FMN, which serve as
cofactors for Complex I (FMN) and Complex II (FAD) of the electron transport chain,
as well as glutathione reductase. Deficiency causes angular stomatitis, cheilosis, and
normocytic anemia. TPP is for decarboxylations, CoA is for acyl transfer, and THF is
for one-carbon transfer.
Correct Answer: B
Q4. A 45-year-old homeless man presents with a photosensitive dermatitis on sun-
exposed skin, chronic diarrhea, and progressive dementia. He reports that his diet
has consisted almost entirely of corn for the past year. Which vitamin deficiency is
responsible for this classic triad?
A. Vitamin B1 (thiamine)
B. Vitamin B6 (pyridoxine)
C. Vitamin B3 (niacin) [CORRECT]
D. Vitamin C (ascorbate)
, 3
Rationale: The "3 D's"—dermatitis, diarrhea, and dementia—are pathognomonic for
pellagra caused by niacin (vitamin B3) deficiency. Corn is low in bioavailable niacin
(bound as niacytin) and low in tryptophan. Thiamine deficiency causes beriberi, B6
deficiency causes seborrheic dermatitis and neuropathy, and vitamin C deficiency
causes scurvy.
Correct Answer: C
Q5. A patient with hyperlipidemia is prescribed high-dose nicotinic acid to lower LDL
cholesterol and raise HDL. Thirty minutes after the first dose, the patient experiences
intense cutaneous flushing, pruritus, and warmth. Which prostaglandin-mediated
mechanism explains this adverse effect?
A. Histamine release from mast cells triggered by NAD⁺ accumulation
B. Prostaglandin D2 release from dermal macrophages via GPR109A activation
[CORRECT]
C. Bradykinin accumulation due to inhibition of angiotensin-converting enzyme
D. Substance P release from cutaneous nerve endings mediated by NADP⁺
Rationale: Niacin binds the GPR109A (HM74A) receptor on dermal Langerhans cells
and adipocytes, stimulating prostaglandin D2 and E2 synthesis, which causes
vasodilation and flushing. This is not histamine-mediated (as with ACE inhibitors), nor
is it related to bradykinin or substance P pathways.
Correct Answer: B
Q6. A biochemistry student is asked to identify the vitamin-derived cofactor that
carries activated acyl groups in both fatty acid synthesis (as malonyl-CoA) and fatty
acid β-oxidation (as acetyl-CoA). Which cofactor is correct?
A. Thiamine pyrophosphate (TPP)
B. Nicotinamide adenine dinucleotide phosphate (NADPH)
C. Coenzyme A (CoA) derived from pantothenate [CORRECT]
D. Biotin-lysine complex (biocytin)
CHEM 210 BIOCHEMISTRY MODULE 8 EXAM ACTUAL
2026/2027 | Nutrition, Vitamins, Minerals & Metabolic
Disease | Geneva College | Complete Questions & Verified
Answers | Pass Guaranteed - A+ Graded
Section 1: Water-Soluble Vitamins (Q1-15)
Q1. A 58-year-old alcoholic patient presents with nystagmus, ataxia, and confusion.
Biochemical analysis reveals elevated blood pyruvate and lactate. Which vitamin-
derived cofactor is deficient, impairing the conversion of pyruvate to acetyl-CoA?
A. Flavin adenine dinucleotide (FAD) derived from riboflavin
B. Nicotinamide adenine dinucleotide (NAD⁺) derived from niacin
C. Thiamine pyrophosphate (TPP) derived from thiamine [CORRECT]
D. Pyridoxal phosphate (PLP) derived from pyridoxine
Rationale: Thiamine pyrophosphate (TPP) is the essential cofactor for pyruvate
dehydrogenase, which converts pyruvate to acetyl-CoA for entry into the TCA cycle.
Thiamine deficiency in alcoholism causes Wernicke-Korsakoff syndrome and lactic
acidosis due to impaired pyruvate dehydrogenase and α-ketoglutarate
dehydrogenase. FAD, NAD⁺, and PLP are not the primary cofactors for this specific
decarboxylation reaction.
Correct Answer: C
Q2. A 3-year-old child in a refugee camp presents with high-output cardiac failure,
peripheral neuropathy, and bilateral foot drop. The diet consists primarily of polished
white rice. Which vitamin deficiency explains this clinical presentation?
A. Vitamin B12 (cobalamin)
B. Vitamin B1 (thiamine) [CORRECT]
C. Vitamin B3 (niacin)
D. Vitamin B6 (pyridoxine)
Rationale: This presentation of high-output cardiac failure (wet beriberi) and
peripheral neuropathy (dry beriberi) is classic for thiamine deficiency. Polished rice
,2
lacks thiamine-rich bran. Niacin deficiency causes pellagra (dermatitis, diarrhea,
dementia), B12 deficiency causes megaloblastic anemia and neurological
degeneration, and B6 deficiency causes seborrheic dermatitis and microcytic anemia.
Correct Answer: B
Q3. A patient with chronic alcoholism and malnutrition develops cheilosis, angular
stomatitis, and a normocytic anemia. Which cofactor pair is most likely deficient,
impairing both the electron transport chain and glutathione reductase activity?
A. Thiamine pyrophosphate (TPP)
B. Flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN) [CORRECT]
C. Coenzyme A (CoA)
D. Tetrahydrofolate (THF)
Rationale: Riboflavin (vitamin B2) is the precursor of FAD and FMN, which serve as
cofactors for Complex I (FMN) and Complex II (FAD) of the electron transport chain,
as well as glutathione reductase. Deficiency causes angular stomatitis, cheilosis, and
normocytic anemia. TPP is for decarboxylations, CoA is for acyl transfer, and THF is
for one-carbon transfer.
Correct Answer: B
Q4. A 45-year-old homeless man presents with a photosensitive dermatitis on sun-
exposed skin, chronic diarrhea, and progressive dementia. He reports that his diet
has consisted almost entirely of corn for the past year. Which vitamin deficiency is
responsible for this classic triad?
A. Vitamin B1 (thiamine)
B. Vitamin B6 (pyridoxine)
C. Vitamin B3 (niacin) [CORRECT]
D. Vitamin C (ascorbate)
, 3
Rationale: The "3 D's"—dermatitis, diarrhea, and dementia—are pathognomonic for
pellagra caused by niacin (vitamin B3) deficiency. Corn is low in bioavailable niacin
(bound as niacytin) and low in tryptophan. Thiamine deficiency causes beriberi, B6
deficiency causes seborrheic dermatitis and neuropathy, and vitamin C deficiency
causes scurvy.
Correct Answer: C
Q5. A patient with hyperlipidemia is prescribed high-dose nicotinic acid to lower LDL
cholesterol and raise HDL. Thirty minutes after the first dose, the patient experiences
intense cutaneous flushing, pruritus, and warmth. Which prostaglandin-mediated
mechanism explains this adverse effect?
A. Histamine release from mast cells triggered by NAD⁺ accumulation
B. Prostaglandin D2 release from dermal macrophages via GPR109A activation
[CORRECT]
C. Bradykinin accumulation due to inhibition of angiotensin-converting enzyme
D. Substance P release from cutaneous nerve endings mediated by NADP⁺
Rationale: Niacin binds the GPR109A (HM74A) receptor on dermal Langerhans cells
and adipocytes, stimulating prostaglandin D2 and E2 synthesis, which causes
vasodilation and flushing. This is not histamine-mediated (as with ACE inhibitors), nor
is it related to bradykinin or substance P pathways.
Correct Answer: B
Q6. A biochemistry student is asked to identify the vitamin-derived cofactor that
carries activated acyl groups in both fatty acid synthesis (as malonyl-CoA) and fatty
acid β-oxidation (as acetyl-CoA). Which cofactor is correct?
A. Thiamine pyrophosphate (TPP)
B. Nicotinamide adenine dinucleotide phosphate (NADPH)
C. Coenzyme A (CoA) derived from pantothenate [CORRECT]
D. Biotin-lysine complex (biocytin)
