UNE BIOCHEMISTRY TESTS COMPILATION
BUNDLE 2026 FULL QUESTIONS AND
CORRECT ANSWERS STUDY GUIDE
GRADED A+
⩥Which of the following enzymes is correctly paired with its activator?
Answer: N-acetylglutamate synthatase; arginine
⩥The urea cycle takes place in which of the following subcellular
locations?
Answer: the cytosol and the mitochondria
⩥Which of the following enzymes is regulated by N-acetylglutamate
(NAGs)?
Answer: CPS I
⩥Which of the following enzymes is the regulatory step in the urea
cycle?
Answer: Carbamoyl phosphate synthetase I (CPS I)
⩥Which of the following statements is consistent with nitrogen transport
in the fasted state?
,Answer: The urea cycle will be active
⩥A comatose infant is brought to the ER. In the course of the
examination, plasma ammonia was found to be elevated 20-fold over
normal values. Urine orotic acid and uracil were both greater than
normal. A defect of which of the following enzymes is the most likely
diagnosis?
Answer: Ornithine transcarbamoylase
⩥Your patient presents with a deficiency of the enzyme that catalyzes
synthesis of N-acetylglutamate (NAGs). Which of the following would
be a consequence of this deficiency in the patient?
Answer: Increased amino acids in the blood
⩥The cellular uptake of LDL increases intracellular cholesterol levels.
This has which of the following impacts on de novo cholesterol
synthesis?
Answer: Increases degradation of HMG-CoA reductase
⩥Dietary cholesterol is primarily transported in the body by which of
the following lipoproteins?
Answer: Chylomicron
,⩥Secondary bile salts are generated by bacterial modification of primary
bile salts in the intestinal lumen. These modifications have which of the
following impacts on bile salt solubility?
Answer: Decrease solubility
⩥A 47-year-old male is prescribed a statin (HMG-CoA reductase
inhibitor) to manage his elevated LDL cholesterol. What is the initial
mechanism of action for obtaining the desired effect in this man?
Answer: Decreasing hepatic cholesterol biosynthesis
⩥A deficiency in the LDL receptor will result in an initial decrease in
which of the following?
Answer: Intracellular cholesterol
⩥A 45-year-old man has a mild heart attack and a history of vascular
disease. He is placed on a Mediterranean diet and statin drug therapy.
Which of the following will be the most likely result of this drug
therapy?
Answer: Low blood LDLs
⩥A 45-year-old man is found to have an elevated serum triglycerides of
> 730mg/dL. He tells you he forgot to fast before his visit and he ate a
full breakfast of bacon and eggs before the labs were drawn. Which of
the following lipoproteins would be the largest contributors to a
measurement of plasma triglycerides in this situation?
, Answer: Chylomicrons and VLDLs
⩥In the reaction catalyzed by cholesterol ester transfer protein (CETP),
the VLDL particle receives which of the following compounds from
HDL particles?
Answer: Cholesterol-ester
⩥In reverse cholesterol transport HDL interacts with the ABCA1
transporter to move cholesterol from the cell to the HDL. This also
requires the activity of which of the following enzyme?
Answer: Lecithin cholesterol acyltransferase (LCAT)
⩥HDL particles interact with VLDL particles to exchange cholesterol
ester for triacylglyerols. Which of the following enzymes is responsible
for this process?
Answer: Cholesterol ester transfer protein (CETP)
⩥Which of the following is a major source of extracellular cholesterol
for human tissues?
Answer: LDLs
⩥An individual is suspected of having a deficiency in branched chain
keto acid dehydrogenase. Supplementation of which of the following
vitamins or cofactors may help resolve this issue?
BUNDLE 2026 FULL QUESTIONS AND
CORRECT ANSWERS STUDY GUIDE
GRADED A+
⩥Which of the following enzymes is correctly paired with its activator?
Answer: N-acetylglutamate synthatase; arginine
⩥The urea cycle takes place in which of the following subcellular
locations?
Answer: the cytosol and the mitochondria
⩥Which of the following enzymes is regulated by N-acetylglutamate
(NAGs)?
Answer: CPS I
⩥Which of the following enzymes is the regulatory step in the urea
cycle?
Answer: Carbamoyl phosphate synthetase I (CPS I)
⩥Which of the following statements is consistent with nitrogen transport
in the fasted state?
,Answer: The urea cycle will be active
⩥A comatose infant is brought to the ER. In the course of the
examination, plasma ammonia was found to be elevated 20-fold over
normal values. Urine orotic acid and uracil were both greater than
normal. A defect of which of the following enzymes is the most likely
diagnosis?
Answer: Ornithine transcarbamoylase
⩥Your patient presents with a deficiency of the enzyme that catalyzes
synthesis of N-acetylglutamate (NAGs). Which of the following would
be a consequence of this deficiency in the patient?
Answer: Increased amino acids in the blood
⩥The cellular uptake of LDL increases intracellular cholesterol levels.
This has which of the following impacts on de novo cholesterol
synthesis?
Answer: Increases degradation of HMG-CoA reductase
⩥Dietary cholesterol is primarily transported in the body by which of
the following lipoproteins?
Answer: Chylomicron
,⩥Secondary bile salts are generated by bacterial modification of primary
bile salts in the intestinal lumen. These modifications have which of the
following impacts on bile salt solubility?
Answer: Decrease solubility
⩥A 47-year-old male is prescribed a statin (HMG-CoA reductase
inhibitor) to manage his elevated LDL cholesterol. What is the initial
mechanism of action for obtaining the desired effect in this man?
Answer: Decreasing hepatic cholesterol biosynthesis
⩥A deficiency in the LDL receptor will result in an initial decrease in
which of the following?
Answer: Intracellular cholesterol
⩥A 45-year-old man has a mild heart attack and a history of vascular
disease. He is placed on a Mediterranean diet and statin drug therapy.
Which of the following will be the most likely result of this drug
therapy?
Answer: Low blood LDLs
⩥A 45-year-old man is found to have an elevated serum triglycerides of
> 730mg/dL. He tells you he forgot to fast before his visit and he ate a
full breakfast of bacon and eggs before the labs were drawn. Which of
the following lipoproteins would be the largest contributors to a
measurement of plasma triglycerides in this situation?
, Answer: Chylomicrons and VLDLs
⩥In the reaction catalyzed by cholesterol ester transfer protein (CETP),
the VLDL particle receives which of the following compounds from
HDL particles?
Answer: Cholesterol-ester
⩥In reverse cholesterol transport HDL interacts with the ABCA1
transporter to move cholesterol from the cell to the HDL. This also
requires the activity of which of the following enzyme?
Answer: Lecithin cholesterol acyltransferase (LCAT)
⩥HDL particles interact with VLDL particles to exchange cholesterol
ester for triacylglyerols. Which of the following enzymes is responsible
for this process?
Answer: Cholesterol ester transfer protein (CETP)
⩥Which of the following is a major source of extracellular cholesterol
for human tissues?
Answer: LDLs
⩥An individual is suspected of having a deficiency in branched chain
keto acid dehydrogenase. Supplementation of which of the following
vitamins or cofactors may help resolve this issue?
