HED201 Human Nutrition
Midterm Exam Review
(Questions & Solutions)
2025
©2025
, Question 1:
In patients with insulin resistance, which metabolic pathway is commonly
upregulated to provide the reducing power (NADPH) required for de
novo lipogenesis?
a) Carnitine shuttle
b) Pentose phosphate pathway
c) Tricarboxylic acid cycle
d) β‑oxidation
Correct ANS: b) Pentose phosphate pathway
Rationale: In insulin-resistant states, excess glucose is often diverted to
the pentose phosphate pathway to generate NADPH, which is essential
for fatty acid synthesis (de novo lipogenesis).
---
Question 2:
Which essential fatty acid deficiency is most likely to impair growth and
increase inflammation?
a) Oleic acid
b) Linoleic acid
c) Stearic acid
d) Palmitic acid
Correct ANS: b) Linoleic acid
Rationale: Linoleic acid, an omega‑6 fatty acid that must be obtained
from the diet, is critical for growth and normal inflammatory responses.
Its deficiency can lead to growth retardation and altered immune
function.
---
©2025
, Question 3:
Which micronutrient is a crucial cofactor in the electron transport chain,
particularly in cytochrome enzymes, and is essential for ATP production?
a) Magnesium
b) Zinc
c) Iron
d) Selenium
Correct ANS: c) Iron
Rationale: Iron is a key component of cytochromes in the electron
transport chain, facilitating electron transfer and ATP synthesis.
Deficiency can impair energy metabolism.
---
Question 4:
Polymorphisms in the MTHFR gene can reduce the conversion of folate
into its active form. This alteration primarily affects which metabolic
parameter?
a) Homocysteine clearance
b) Vitamin D absorption
c) Omega‑3 fatty acid synthesis
d) Glycolysis efficiency
Correct ANS: a) Homocysteine clearance
Rationale: Reduced MTHFR enzyme activity hinders the conversion of
folate to its active form (5‑methyl tetrahydrofolate), resulting in elevated
homocysteine levels and a higher risk of cardiovascular disease.
---
Question 5:
Which method is considered the most direct and comprehensive for
assessing dietary protein adequacy in a clinical research setting?
a) Serum albumin measurement
©2025
, b) Prealbumin measurement
c) Nitrogen balance calculation
d) Body mass index evaluation
Correct ANS: c) Nitrogen balance calculation
Rationale: Nitrogen balance studies provide a direct measure of the
balance between protein intake and excretion, reflecting the adequacy of
protein metabolism over time.
---
Question 6:
Which micronutrient acts as a cofactor in the conversion of
25‑hydroxyvitamin D to its active form (1,25‑dihydroxyvitamin D),
thereby influencing calcium homeostasis?
a) Calcium
b) Magnesium
c) Zinc
d) Phosphorus
Correct ANS: b) Magnesium
Rationale: Magnesium is essential for many enzymatic reactions,
including those involved in vitamin D activation, which in turn affects
calcium absorption and bone metabolism.
---
Question 7:
A patient with a malabsorption syndrome presents with impaired night
vision. Which fat‑soluble vitamin deficiency is most consistent with these
symptoms?
a) Vitamin D
b) Vitamin E
c) Vitamin K
d) Vitamin A
©2025
Midterm Exam Review
(Questions & Solutions)
2025
©2025
, Question 1:
In patients with insulin resistance, which metabolic pathway is commonly
upregulated to provide the reducing power (NADPH) required for de
novo lipogenesis?
a) Carnitine shuttle
b) Pentose phosphate pathway
c) Tricarboxylic acid cycle
d) β‑oxidation
Correct ANS: b) Pentose phosphate pathway
Rationale: In insulin-resistant states, excess glucose is often diverted to
the pentose phosphate pathway to generate NADPH, which is essential
for fatty acid synthesis (de novo lipogenesis).
---
Question 2:
Which essential fatty acid deficiency is most likely to impair growth and
increase inflammation?
a) Oleic acid
b) Linoleic acid
c) Stearic acid
d) Palmitic acid
Correct ANS: b) Linoleic acid
Rationale: Linoleic acid, an omega‑6 fatty acid that must be obtained
from the diet, is critical for growth and normal inflammatory responses.
Its deficiency can lead to growth retardation and altered immune
function.
---
©2025
, Question 3:
Which micronutrient is a crucial cofactor in the electron transport chain,
particularly in cytochrome enzymes, and is essential for ATP production?
a) Magnesium
b) Zinc
c) Iron
d) Selenium
Correct ANS: c) Iron
Rationale: Iron is a key component of cytochromes in the electron
transport chain, facilitating electron transfer and ATP synthesis.
Deficiency can impair energy metabolism.
---
Question 4:
Polymorphisms in the MTHFR gene can reduce the conversion of folate
into its active form. This alteration primarily affects which metabolic
parameter?
a) Homocysteine clearance
b) Vitamin D absorption
c) Omega‑3 fatty acid synthesis
d) Glycolysis efficiency
Correct ANS: a) Homocysteine clearance
Rationale: Reduced MTHFR enzyme activity hinders the conversion of
folate to its active form (5‑methyl tetrahydrofolate), resulting in elevated
homocysteine levels and a higher risk of cardiovascular disease.
---
Question 5:
Which method is considered the most direct and comprehensive for
assessing dietary protein adequacy in a clinical research setting?
a) Serum albumin measurement
©2025
, b) Prealbumin measurement
c) Nitrogen balance calculation
d) Body mass index evaluation
Correct ANS: c) Nitrogen balance calculation
Rationale: Nitrogen balance studies provide a direct measure of the
balance between protein intake and excretion, reflecting the adequacy of
protein metabolism over time.
---
Question 6:
Which micronutrient acts as a cofactor in the conversion of
25‑hydroxyvitamin D to its active form (1,25‑dihydroxyvitamin D),
thereby influencing calcium homeostasis?
a) Calcium
b) Magnesium
c) Zinc
d) Phosphorus
Correct ANS: b) Magnesium
Rationale: Magnesium is essential for many enzymatic reactions,
including those involved in vitamin D activation, which in turn affects
calcium absorption and bone metabolism.
---
Question 7:
A patient with a malabsorption syndrome presents with impaired night
vision. Which fat‑soluble vitamin deficiency is most consistent with these
symptoms?
a) Vitamin D
b) Vitamin E
c) Vitamin K
d) Vitamin A
©2025
