UNE Biochemistry Final Exam 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
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. |Incisional |biopsy |of |one |of |the |spots |on |his |hands |
and |urine |sample |tested |positive |for |or |homogentisic |acid. |Based |on |these |findings |a |diagnosis
|of |alkaptonuria |is |made. |This |diagnosis |is |consistent |with |a |deficiency |in |which |of |the |
following |enzymes? |- |CORRECT |ANSWER✔✔-Homogentisate |oxidase
Methotrexate |is |a |potent |anticancer |agent |that |starves |dividing |cells |of |deoxyribonucleotides |
through |direct |inhibition |of |which |of |the |following |processes? |- |CORRECT |ANSWER✔✔-
Metabolism |of |folic |acid
A |47-year-old |man |complains |of |pain |in |the |joints |of |his |left |big |toe, |which |are |obviously |
swollen |and |tender. |The |pain |has |been |chronic |but |became |intolerable |the |day |after |
Thanksgiving |when |he |had |a |large |meal |and |several |glasses |of |red |wine. |Based |on |this |
information |a |diagnosis |of |gout |is |made. |Which |of |the |following |is |involved |in |the |
pathophysiology |of |this |patient's |condition? |- |CORRECT |ANSWER✔✔-Elevated |uric |acid
Which |of |the |following |is |the |common |intermediate |for |purine |synthesis? |- |CORRECT |
ANSWER✔✔-Inosine |monophosphate
The |ribonucleotide |reductase |is |important |for |converting |ribose |bases |to |the |deoxy |form. |This |
conversion |is |coupled |with |the |oxidation |of |which |of |the |following |compounds? |- |CORRECT |
ANSWER✔✔-Thioredoxin
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
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. |Incisional |biopsy |of |one |of |the |spots |on |his |hands |
and |urine |sample |tested |positive |for |or |homogentisic |acid. |Based |on |these |findings |a |diagnosis
|of |alkaptonuria |is |made. |This |diagnosis |is |consistent |with |a |deficiency |in |which |of |the |
following |enzymes? |- |CORRECT |ANSWER✔✔-Homogentisate |oxidase
Methotrexate |is |a |potent |anticancer |agent |that |starves |dividing |cells |of |deoxyribonucleotides |
through |direct |inhibition |of |which |of |the |following |processes? |- |CORRECT |ANSWER✔✔-
Metabolism |of |folic |acid
A |47-year-old |man |complains |of |pain |in |the |joints |of |his |left |big |toe, |which |are |obviously |
swollen |and |tender. |The |pain |has |been |chronic |but |became |intolerable |the |day |after |
Thanksgiving |when |he |had |a |large |meal |and |several |glasses |of |red |wine. |Based |on |this |
information |a |diagnosis |of |gout |is |made. |Which |of |the |following |is |involved |in |the |
pathophysiology |of |this |patient's |condition? |- |CORRECT |ANSWER✔✔-Elevated |uric |acid
Which |of |the |following |is |the |common |intermediate |for |purine |synthesis? |- |CORRECT |
ANSWER✔✔-Inosine |monophosphate
The |ribonucleotide |reductase |is |important |for |converting |ribose |bases |to |the |deoxy |form. |This |
conversion |is |coupled |with |the |oxidation |of |which |of |the |following |compounds? |- |CORRECT |
ANSWER✔✔-Thioredoxin
