UNE Biochemistry Final,
Final, Final Exam Review
UNE medical biochemistry
Questions and Answers Solved
100% Correct
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?
Alanine
Which of the following enzymes is correctly paired with its activator?
N-acetylglutamate synthatase; arginine
The urea cycle takes place in which of the following subcellular locations?
the cytosol and the mitochondria
Which of the following enzymes is regulated by N-acetylglutamate (NAGs)?
CPS I
Which of the following enzymes is the regulatory step in the urea cycle?
Carbamoyl phosphate synthetase I (CPS I)
Which of the following statements is consistent with nitrogen transport in
,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?
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?
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?
Increases degradation of HMG-CoA reductase
Dietary cholesterol is primarily transported in the body by which of the
following lipoproteins?
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?
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?
Decreasing hepatic cholesterol biosynthesis
,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?
Low blood LDLs
We have an expert-written solution to this problem!
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?
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?
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?
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?
Cholesterol ester transfer protein (CETP)
Which of the following is a major source of extracellular cholesterol for
human tissues?
, 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?
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?
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?
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?
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?
Tryptophan
A 52-year- old male sought medical help complaining about progressive
appearance of hyperchromic (hyper pigmented) papules on the edge of the
second finger of both hands. He also complained about darkening of urine.
Final, Final Exam Review
UNE medical biochemistry
Questions and Answers Solved
100% Correct
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?
Alanine
Which of the following enzymes is correctly paired with its activator?
N-acetylglutamate synthatase; arginine
The urea cycle takes place in which of the following subcellular locations?
the cytosol and the mitochondria
Which of the following enzymes is regulated by N-acetylglutamate (NAGs)?
CPS I
Which of the following enzymes is the regulatory step in the urea cycle?
Carbamoyl phosphate synthetase I (CPS I)
Which of the following statements is consistent with nitrogen transport in
,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?
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?
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?
Increases degradation of HMG-CoA reductase
Dietary cholesterol is primarily transported in the body by which of the
following lipoproteins?
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?
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?
Decreasing hepatic cholesterol biosynthesis
,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?
Low blood LDLs
We have an expert-written solution to this problem!
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?
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?
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?
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?
Cholesterol ester transfer protein (CETP)
Which of the following is a major source of extracellular cholesterol for
human tissues?
, 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?
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?
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?
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?
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?
Tryptophan
A 52-year- old male sought medical help complaining about progressive
appearance of hyperchromic (hyper pigmented) papules on the edge of the
second finger of both hands. He also complained about darkening of urine.
