Comprehensive Final Exam (Qns & Ans)
2025
Question 1
A 55-year-old patient with a history of alcoholism presents with
symptoms of confusion and ataxia. Which nutrient deficiency is
most likely responsible for these neurological signs due to its role
as a coenzyme in carbohydrate metabolism?
- A. Niacin
- B. Thiamine
- C. Riboflavin
- D. Pyridoxine
Correct ANS: B
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, Rationale:
Thiamine (vitamin B₁) is essential for the decarboxylation of
pyruvate via thiamine pyrophosphate. Its deficiency, common in
chronic alcoholics, leads to Wernicke-Korsakoff syndrome and
neurological deficits.
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Question 2
A patient on a weight-loss regimen complains of dry skin and hair
loss. Which fatty acid is considered essential and must be
obtained from the diet to prevent deficiency symptoms?
- A. Oleic acid
- B. Linoleic acid
- C. Palmitic acid
- D. Stearic acid
Correct ANS: B
Rationale:
Linoleic acid, an omega‑6 fatty acid, is essential because it cannot
be synthesized de novo by the human body. Its deficiency can
affect skin integrity and hair health.
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Question 3
The absorption of fat‑soluble vitamins requires the formation of
micelles. Which component is crucial for micelle formation in the
small intestine?
- A. Gastric acid
- B. Bile salts
- C. Pancreatic proteases
- D. Salivary amylase
Correct ANS: B
Rationale:
Bile salts emulsify dietary fats to form micelles, which enhance
the absorption of fat‑soluble vitamins (A, D, E, and K) in the
small intestine.
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Question 4
During the intestinal absorption of iron, which step is essential for
its uptake by enterocytes in the duodenum?
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, - A. Oxidation of ferrous iron to ferric iron
- B. Reduction of ferric iron to ferrous iron
- C. Complexation with bile salts
- D. Binding to transferrin in the lumen
Correct ANS: B
Rationale:
In the duodenum, ferric (Fe³⁺) iron must be reduced to the ferrous
(Fe²⁺) form—primarily by duodenal cytochrome B—to be
efficiently absorbed via the divalent metal transporter (DMT-1).
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Question 5
A patient being treated for hypercholesterolemia is prescribed a
medication that inhibits the rate-limiting step of cholesterol
synthesis. Which enzyme does this drug target?
- A. Acetyl-CoA carboxylase
- B. HMG-CoA reductase
- C. Carnitine acyltransferase
- D. Lipoprotein lipase
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