UNE Biochemistry Final UPDATED
Questions with CORRECT Answers
The glucose-alanine cycle is a method of transferring ammonia from the skeletal muscle to the
liver. In this process the non-toxic carrier of ammonia is which of the following compounds? -
CORRECT ANSWER - Alanine
Which of the following enzymes is correctly paired with its activator? - CORRECT
ANSWER - N-acetylglutamate synthatase; arginine
The urea cycle takes place in which of the following subcellular locations? - CORRECT
ANSWER - the cytosol and the mitochondria
Which of the following enzymes is regulated by N-acetylglutamate (NAGs)? - CORRECT
ANSWER - CPS I
Which of the following enzymes is the regulatory step in the urea cycle? - CORRECT
ANSWER - Carbamoyl phosphate synthetase I (CPS I)
Which of the following statements is consistent with nitrogen transport in the fasted state? -
CORRECT 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? -
CORRECT 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? - CORRECT 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? - CORRECT ANSWER - Increases
degradation of HMG-CoA reductase
Dietary cholesterol is primarily transported in the body by which of the following lipoproteins? -
CORRECT 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? -
CORRECT 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? - CORRECT ANSWER - Decreasing hepatic cholesterol biosynthesis
A deficiency in the LDL receptor will result in an initial decrease in which of the following? -
CORRECT 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? - CORRECT 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? - CORRECT 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? - CORRECT 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? -
CORRECT 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? - CORRECT ANSWER -
Cholesterol ester transfer protein (CETP)
Which of the following is a major source of extracellular cholesterol for human tissues? -
CORRECT 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? -
CORRECT ANSWER - Thiamine
A 55-year old man presents to his primary care physician with bouts of dizziness and confusion.
He is diagnosed with hyperhomocysteinemia due to a deficiency of cystathionine-ß synthase. In
this individual which of the following amino acids could potentially become essential? -
CORRECT ANSWER - Cysteine
Phenylketonuria can be caused by an enzymatic deficiency or it can present due to a deficiency
in which of the following required metabolic cofactors? - CORRECT ANSWER -
Tetrahydrobiopterin (BH4)
A 17-year old female presents to her primary care and is diagnosed with a Vitamin B12
(cobalamin) deficiency. In this individual, which of the following reactions would be
compromised? - CORRECT ANSWER - Conversion of methyl malonyl-Co A to succinyl-
CoA
A 15-year-old female presents to her pediatrician with concerns over her inability to sleep,
increased feelings of depression and generalized fatigue. A full laboratory work-up is ordered
and based on these findings she is diagnosed with a melatonin deficiency. Based on this
information, metabolism of which of the following amino acids is likely impaired? - CORRECT
ANSWER - Tryptophan
Questions with CORRECT Answers
The glucose-alanine cycle is a method of transferring ammonia from the skeletal muscle to the
liver. In this process the non-toxic carrier of ammonia is which of the following compounds? -
CORRECT ANSWER - Alanine
Which of the following enzymes is correctly paired with its activator? - CORRECT
ANSWER - N-acetylglutamate synthatase; arginine
The urea cycle takes place in which of the following subcellular locations? - CORRECT
ANSWER - the cytosol and the mitochondria
Which of the following enzymes is regulated by N-acetylglutamate (NAGs)? - CORRECT
ANSWER - CPS I
Which of the following enzymes is the regulatory step in the urea cycle? - CORRECT
ANSWER - Carbamoyl phosphate synthetase I (CPS I)
Which of the following statements is consistent with nitrogen transport in the fasted state? -
CORRECT 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? -
CORRECT 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? - CORRECT 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? - CORRECT ANSWER - Increases
degradation of HMG-CoA reductase
Dietary cholesterol is primarily transported in the body by which of the following lipoproteins? -
CORRECT 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? -
CORRECT 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? - CORRECT ANSWER - Decreasing hepatic cholesterol biosynthesis
A deficiency in the LDL receptor will result in an initial decrease in which of the following? -
CORRECT 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? - CORRECT 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? - CORRECT 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? - CORRECT 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? -
CORRECT 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? - CORRECT ANSWER -
Cholesterol ester transfer protein (CETP)
Which of the following is a major source of extracellular cholesterol for human tissues? -
CORRECT 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? -
CORRECT ANSWER - Thiamine
A 55-year old man presents to his primary care physician with bouts of dizziness and confusion.
He is diagnosed with hyperhomocysteinemia due to a deficiency of cystathionine-ß synthase. In
this individual which of the following amino acids could potentially become essential? -
CORRECT ANSWER - Cysteine
Phenylketonuria can be caused by an enzymatic deficiency or it can present due to a deficiency
in which of the following required metabolic cofactors? - CORRECT ANSWER -
Tetrahydrobiopterin (BH4)
A 17-year old female presents to her primary care and is diagnosed with a Vitamin B12
(cobalamin) deficiency. In this individual, which of the following reactions would be
compromised? - CORRECT ANSWER - Conversion of methyl malonyl-Co A to succinyl-
CoA
A 15-year-old female presents to her pediatrician with concerns over her inability to sleep,
increased feelings of depression and generalized fatigue. A full laboratory work-up is ordered
and based on these findings she is diagnosed with a melatonin deficiency. Based on this
information, metabolism of which of the following amino acids is likely impaired? - CORRECT
ANSWER - Tryptophan
