UNE Medical Biochemistry
UNE Medical Biochemistry Final Exam
2025 Graded A+
A 55-year-old male is diagnosed with Type 2 diabetes and his current presentation is
consistent with a lack of insulin production. Serum levels of free fatty acids were
elevated in this individual primarily due to increased activity of which of the following
enzymes?
Carnitine palmitoyl transferase I
Carbamoyl phosphate synthetase I
Hormone-sensitive lipase
Glutamate dehydrogenase -Correct Answer ✔Hormone-sensitive lipase
β- oxidation of long-chain fatty acids is inhibited by:
Pantothenic Acid (vitamin B5)
Carnitine
Malonyl-CoA
Fatty acids -Correct Answer ✔Malonyl-CoA
Which of the following represents the correct sequence of events in a cycle of β-
oxidation beginning with a saturated fatty acyl-CoA?
NAD+-coupled oxidation, FAD-coupled oxidation, hydration, thiolytic cleavage
NAD+-coupled oxidation, hydration, FAD-coupled oxidation, thiolytic cleavage
hydration, FAD-coupled oxidation, NAD+-coupled oxidation, thiolytic cleavage
FAD-coupled oxidation, hydration, NAD+-coupled oxidation, thiolytic cleavage
UNE Medical Biochemistry
,UNE Medical Biochemistry
FAD-coupled oxidation, NAD+-coupled oxidation, hydration, thiolytic cleavage -Correct
Answer ✔FAD-coupled oxidation, hydration, NAD+-coupled oxidation, thiolytic cleavage
Glucose cannot be synthesized from the β-oxidation of even chain fatty acids because:
Insulin levels are elevated when fatty acids are being oxidized
The acetyl-CoA produced from β-oxidation is completely oxidized in the TCA cycle
Acetyl-CoA produced in the β-oxidation of fatty acids cannot be transported out of the
mitochondrial matrix
Gluconeogenesis is inhibited by acetyl-CoA produced in the β-oxidation of fatty acids -
Correct Answer ✔The acetyl-CoA produced from β-oxidation is completely oxidized in
the TCA cycle
A well, 2-year-old female presents to the clinic with symptoms of a viral illness. Her
parents report she has had bouts of vomiting and diarrhea over the last 24 hours. This
morning they could barely wake her from her crib and she was very weak. Laboratory
tests show low blood glucose (hypoglycemia) and elevated liver enzymes. There are no
ketones present in her urine. The child is hospitalized and glucose is administered I.V.
Additional laboratory analysis showed elevated medium-chain fatty acylcarnitines in
blood and 6-8 carbon dicarboxylic acids in the urine. Which of the following
abnormalities is the most likely diagnosis for this child?
Mitochondrial defect in fatty acid transport
Defect of medium-chain fatty acyl synthetase
Carnitine deficiency
Defect of medium-chain coenzyme A dehydrogenase
Mitochondrial defect in the electron transport chain -Correct Answer ✔Defect of
medium-chain coenzyme A dehydrogenase
UNE Medical Biochemistry
, UNE Medical Biochemistry
A 1-year-old female presents to the emergency room with hypoglycemia following a
brief seizure. After laboratory tests, a deficiency in β-oxidation is confirmed. This could
potentially be caused by a deficiency in an enzyme or reduced levels of which of the
following cofactors are required for this process?
Pyridoxal phosphate
Carnitine
Thiamine
Biotin -Correct Answer ✔Carnitine
An 11-year-old female is brought to the emergency department by her parent. They
report she has recently been very thirsty and needs to make frequent trips to the
bathroom. Physical examination revealed a thin girl in the 30th percentile for height and
weight. A rapid dipstick test revealed glucose in her urine. Evaluation of this girl's blood
would reveal decreased levels of which of the following compounds or hormones?
Glutamine
Ketones
Fatty acids
Insulin
Glucose -Correct Answer ✔Insulin
What is the compound formed from the spontaneous decarboxylation of acetoacetate in
the blood that is responsible for a fruity odor on the breath of someone with
ketonemia?
β-hydroxybutyrate
Succinyl-CoA
UNE Medical Biochemistry
UNE Medical Biochemistry Final Exam
2025 Graded A+
A 55-year-old male is diagnosed with Type 2 diabetes and his current presentation is
consistent with a lack of insulin production. Serum levels of free fatty acids were
elevated in this individual primarily due to increased activity of which of the following
enzymes?
Carnitine palmitoyl transferase I
Carbamoyl phosphate synthetase I
Hormone-sensitive lipase
Glutamate dehydrogenase -Correct Answer ✔Hormone-sensitive lipase
β- oxidation of long-chain fatty acids is inhibited by:
Pantothenic Acid (vitamin B5)
Carnitine
Malonyl-CoA
Fatty acids -Correct Answer ✔Malonyl-CoA
Which of the following represents the correct sequence of events in a cycle of β-
oxidation beginning with a saturated fatty acyl-CoA?
NAD+-coupled oxidation, FAD-coupled oxidation, hydration, thiolytic cleavage
NAD+-coupled oxidation, hydration, FAD-coupled oxidation, thiolytic cleavage
hydration, FAD-coupled oxidation, NAD+-coupled oxidation, thiolytic cleavage
FAD-coupled oxidation, hydration, NAD+-coupled oxidation, thiolytic cleavage
UNE Medical Biochemistry
,UNE Medical Biochemistry
FAD-coupled oxidation, NAD+-coupled oxidation, hydration, thiolytic cleavage -Correct
Answer ✔FAD-coupled oxidation, hydration, NAD+-coupled oxidation, thiolytic cleavage
Glucose cannot be synthesized from the β-oxidation of even chain fatty acids because:
Insulin levels are elevated when fatty acids are being oxidized
The acetyl-CoA produced from β-oxidation is completely oxidized in the TCA cycle
Acetyl-CoA produced in the β-oxidation of fatty acids cannot be transported out of the
mitochondrial matrix
Gluconeogenesis is inhibited by acetyl-CoA produced in the β-oxidation of fatty acids -
Correct Answer ✔The acetyl-CoA produced from β-oxidation is completely oxidized in
the TCA cycle
A well, 2-year-old female presents to the clinic with symptoms of a viral illness. Her
parents report she has had bouts of vomiting and diarrhea over the last 24 hours. This
morning they could barely wake her from her crib and she was very weak. Laboratory
tests show low blood glucose (hypoglycemia) and elevated liver enzymes. There are no
ketones present in her urine. The child is hospitalized and glucose is administered I.V.
Additional laboratory analysis showed elevated medium-chain fatty acylcarnitines in
blood and 6-8 carbon dicarboxylic acids in the urine. Which of the following
abnormalities is the most likely diagnosis for this child?
Mitochondrial defect in fatty acid transport
Defect of medium-chain fatty acyl synthetase
Carnitine deficiency
Defect of medium-chain coenzyme A dehydrogenase
Mitochondrial defect in the electron transport chain -Correct Answer ✔Defect of
medium-chain coenzyme A dehydrogenase
UNE Medical Biochemistry
, UNE Medical Biochemistry
A 1-year-old female presents to the emergency room with hypoglycemia following a
brief seizure. After laboratory tests, a deficiency in β-oxidation is confirmed. This could
potentially be caused by a deficiency in an enzyme or reduced levels of which of the
following cofactors are required for this process?
Pyridoxal phosphate
Carnitine
Thiamine
Biotin -Correct Answer ✔Carnitine
An 11-year-old female is brought to the emergency department by her parent. They
report she has recently been very thirsty and needs to make frequent trips to the
bathroom. Physical examination revealed a thin girl in the 30th percentile for height and
weight. A rapid dipstick test revealed glucose in her urine. Evaluation of this girl's blood
would reveal decreased levels of which of the following compounds or hormones?
Glutamine
Ketones
Fatty acids
Insulin
Glucose -Correct Answer ✔Insulin
What is the compound formed from the spontaneous decarboxylation of acetoacetate in
the blood that is responsible for a fruity odor on the breath of someone with
ketonemia?
β-hydroxybutyrate
Succinyl-CoA
UNE Medical Biochemistry
