Page 1 of 154
UNE Medical Biochemistry Unit 3 EXAM
LATEST VERSION 2026 QUESTIONS AND
CORRECT DETAILED ANSWERS
1. A 45-year-old male has just finished a high-carbohydrate
meal. Which metabolic pathway is primarily active in his
hepatocytes?
A) Gluconeogenesis
B) Glycogenolysis
C) Glycogenesis ✅
D) β-oxidation
Rationale: After a high-carb meal, insulin rises, promoting
glycogenesis (glycogen synthesis) in liver and muscle.
Gluconeogenesis and glycogenolysis are suppressed; β-
oxidation is active during fasting.
,Page 2 of 154
2. During an overnight fast, which hormone maintains blood
glucose by activating hepatic glycogenolysis?
A) Insulin
B) Glucagon ✅
C) Epinephrine
D) Cortisol
Rationale: Glucagon is the primary counterregulatory
hormone during short-term fasting, stimulating glycogen
breakdown. Epinephrine is more for acute stress; cortisol acts
over hours.
3. A patient with type 1 diabetes mellitus (T1DM) misses his
insulin dose before breakfast. Which metabolic state
predominates by late morning?
A) Fed state
B) Postprandial glycogenesis
C) Accelerated gluconeogenesis and ketogenesis ✅
D) Lipoprotein lipase activation
,Page 3 of 154
Rationale: Insulin deficiency permits unopposed glucagon
action → ↑ gluconeogenesis, ↑ lipolysis, ↑ ketogenesis →
hyperglycemia and ketosis.
4. Which enzyme is the rate-limiting step of glycolysis?
A) Pyruvate kinase
B) Hexokinase
C) Glucokinase
D) Phosphofructokinase-1 (PFK-1) ✅
Rationale: PFK-1 is the major regulated step; inhibited by ATP
and citrate, activated by AMP and fructose-2,6-bisphosphate.
5. A premature infant develops hypoglycemia despite
adequate glycogen stores. Which enzyme deficiency is most
likely?
A) Glucose-6-phosphatase ✅
B) Liver glycogen phosphorylase
C) Glycogen synthase
D) UDP-glucose pyrophosphorylase
, Page 4 of 154
Rationale: Glucose-6-phosphatase deficiency (von Gierke
disease) prevents release of free glucose from G6P, causing
severe fasting hypoglycemia.
6. In the well-fed state, pyruvate dehydrogenase (PDH) is:
A) Phosphorylated and active
B) Dephosphorylated and active ✅
C) Phosphorylated and inactive
D) Dephosphorylated and inactive
Rationale: Insulin promotes PDH dephosphorylation (active),
directing pyruvate to acetyl-CoA for fatty acid synthesis.
7. A 55-year-old with obesity and acanthosis nigricans has
fasting glucose 130 mg/dL, insulin 25 μU/mL (elevated). This
pattern indicates:
A) Type 1 diabetes
B) Insulin resistance ✅
C) Glucagonoma
D) Glycogen storage disease
UNE Medical Biochemistry Unit 3 EXAM
LATEST VERSION 2026 QUESTIONS AND
CORRECT DETAILED ANSWERS
1. A 45-year-old male has just finished a high-carbohydrate
meal. Which metabolic pathway is primarily active in his
hepatocytes?
A) Gluconeogenesis
B) Glycogenolysis
C) Glycogenesis ✅
D) β-oxidation
Rationale: After a high-carb meal, insulin rises, promoting
glycogenesis (glycogen synthesis) in liver and muscle.
Gluconeogenesis and glycogenolysis are suppressed; β-
oxidation is active during fasting.
,Page 2 of 154
2. During an overnight fast, which hormone maintains blood
glucose by activating hepatic glycogenolysis?
A) Insulin
B) Glucagon ✅
C) Epinephrine
D) Cortisol
Rationale: Glucagon is the primary counterregulatory
hormone during short-term fasting, stimulating glycogen
breakdown. Epinephrine is more for acute stress; cortisol acts
over hours.
3. A patient with type 1 diabetes mellitus (T1DM) misses his
insulin dose before breakfast. Which metabolic state
predominates by late morning?
A) Fed state
B) Postprandial glycogenesis
C) Accelerated gluconeogenesis and ketogenesis ✅
D) Lipoprotein lipase activation
,Page 3 of 154
Rationale: Insulin deficiency permits unopposed glucagon
action → ↑ gluconeogenesis, ↑ lipolysis, ↑ ketogenesis →
hyperglycemia and ketosis.
4. Which enzyme is the rate-limiting step of glycolysis?
A) Pyruvate kinase
B) Hexokinase
C) Glucokinase
D) Phosphofructokinase-1 (PFK-1) ✅
Rationale: PFK-1 is the major regulated step; inhibited by ATP
and citrate, activated by AMP and fructose-2,6-bisphosphate.
5. A premature infant develops hypoglycemia despite
adequate glycogen stores. Which enzyme deficiency is most
likely?
A) Glucose-6-phosphatase ✅
B) Liver glycogen phosphorylase
C) Glycogen synthase
D) UDP-glucose pyrophosphorylase
, Page 4 of 154
Rationale: Glucose-6-phosphatase deficiency (von Gierke
disease) prevents release of free glucose from G6P, causing
severe fasting hypoglycemia.
6. In the well-fed state, pyruvate dehydrogenase (PDH) is:
A) Phosphorylated and active
B) Dephosphorylated and active ✅
C) Phosphorylated and inactive
D) Dephosphorylated and inactive
Rationale: Insulin promotes PDH dephosphorylation (active),
directing pyruvate to acetyl-CoA for fatty acid synthesis.
7. A 55-year-old with obesity and acanthosis nigricans has
fasting glucose 130 mg/dL, insulin 25 μU/mL (elevated). This
pattern indicates:
A) Type 1 diabetes
B) Insulin resistance ✅
C) Glucagonoma
D) Glycogen storage disease
