ACBN Practice Questions 3 — Questions and Answers
Question 1: Which lipoprotein is primarily responsible for transporting cholesterol from the liver to peripheral tissues?
- HDL
- LDL (Correct answer)
- VLDL
- Chylomicrons
Correct answer: LDL
LDL (low-density lipoprotein) transports cholesterol from the liver to peripheral tissues and is the primary carrier of cholesterol in circulation.
Question 2: A patient with chronic kidney disease stage 4 should typically restrict which nutrient to slow disease progression?
- Carbohydrate
- Protein (Correct answer)
- Unsaturated fat
- Soluble fiber
Correct answer: Protein
Protein restriction in CKD stage 4 reduces the nitrogen load on failing kidneys and can slow the rate of GFR decline.
Question 3: The body mass index (BMI) threshold for obesity classification in adults according to standard clinical guidelines is:
- BMI ≥ 25 kg/m²
- BMI ≥ 27 kg/m²
- BMI ≥ 30 kg/m² (Correct answer)
- BMI ≥ 35 kg/m²
Correct answer: BMI ≥ 30 kg/m²
A BMI of 30 kg/m² or greater is classified as obesity (Class I), while 25-29.9 is overweight, according to WHO and CDC guidelines.
Question 4: Which vitamin functions as a coenzyme in over 100 enzymatic reactions and is crucial for amino acid metabolism and neurotransmitter synthesis?
- Vitamin B1 (Thiamine)
- Vitamin B2 (Riboflavin)
- Vitamin B6 (Pyridoxine) (Correct answer)
- Vitamin B12 (Cobalamin)
Correct answer: Vitamin B6 (Pyridoxine)
Vitamin B6 (pyridoxine), as pyridoxal phosphate (PLP), is a coenzyme in over 100 enzymatic reactions, particularly transamination and decarboxylation in amino acid metabolism.
Question 5: The Mifflin-St Jeor equation is primarily used to estimate which component of energy expenditure?
- Thermic effect of food
- Physical activity level
- Resting metabolic rate (RMR) (Correct answer)
- Total daily energy expenditure
Correct answer: Resting metabolic rate (RMR)
The Mifflin-St Jeor equation estimates resting metabolic rate using body weight, height, age, and sex, and is considered one of the most accurate predictive equations for RMR.
Question 6: In the context of enteral nutrition, a gastric residual volume (GRV) above what threshold typically prompts clinical reassessment for aspiration risk?
- 50 mL
- 100 mL
- 200-250 mL (Correct answer)
- 500 mL
Correct answer: 200-250 mL
A gastric residual volume above 200-250 mL is generally the clinical threshold that prompts reassessment of enteral feeding tolerance and aspiration risk.
Question 7: Which sugar alcohol is most commonly associated with a significant laxative effect due to its incomplete absorption in the small intestine?
- Erythritol
- Sorbitol (Correct answer)
- Xylitol
- Mannitol
Correct answer: Sorbitol
Sorbitol is poorly absorbed in the small intestine and is fermented by colonic bacteria, causing osmotic diarrhea and bloating at moderate to high intakes.
ACBN Practice Questions 3
Which lipoprotein is primarily responsible for transporting cholesterol from the liver to peripheral tissues?