Question 1

Heme biosynthesis

Accepted Answer

A)  requires that synthesis of the protoporphryin ring occur in the mitochondria due to difficulties in transporting large molecule.
B)  is inhibited in lead poisoning.
C)  can be completed using enzymes from the cytosol.
D)  A and B
E)  A,B,and CF) All of the above
G) C) and E)

Question 2

The pictured compound,glutamate-5-semialdehyde,is an intermediate in the biosynthesis of which of the following amino acids?

Accepted Answer

A)  histidine
B)  arginine
C)  methionine
D)  threonine
E)  More than one of the above is made from this intermediate.F) A) and C)
G) A) and D)

Question 3

Matching
Choose the correct answer from the list.Not all the answers will be used.

-ATP-dependent degradation of ubiquitinated proteins is mediated by ______.

Accepted Answer

A)   ribosomes
B)   jaundice
C)   channeling
D)   26S proteasome
E)   glutamine synthetaseF)  alanineG)  glutamateH)  vitamin B6I)  anammoxJ)  glutamine transferaseK)  THFL)  autotrophM)  vitamin DN)  lysosomesO)  diazotrophsP) G) and H)
Q) B) and D)

Question 4

Matching
Choose the correct answer from the list.Not all the answers will be used.

-Aminotransferases utilize a coenzyme synthesized from ______.

Accepted Answer

A)   ribosomes
B)   jaundice
C)   channeling
D)   26S proteasome
E)   glutamine synthetaseF)  alanineG)  glutamateH)  vitamin B6I)  anammoxJ)  glutamine transferaseK)  THFL)  autotrophM)  vitamin DN)  lysosomesO)  diazotrophsP) C) and K)
Q) None of the above H

Question 5

Which of the following statements about maple syrup urine disease is FALSE?
(I) It is caused by a genetic deficiency in the enzyme BCKDH.
(II) The disease is fatal unless promptly treated.
(III) There is a buildup of the branched-chain  α\alphaα -keto acids.
(IV) Patients with the disease excrete urine that smells like maple syrup.

Accepted Answer

A)  I only
B)  II only
C)  I,III
D)  III,IV
E)  All of the statements are true. F) B) and D)
G) A) and B)

Question 6

Which of the following statements about tryptophan synthase is FALSE?

Accepted Answer

A)  Indole can pass between active sites via a channel in the enzyme.
B)  Tryptophan synthase catalyzes two distinct reaction steps to form tryptophan.
C)  The enzyme is a tetramer of four identical subunits.
D)  The enzyme has two states,an "open" and "closed",to ensure that bound indole is not lost to solvent.
E)  The indole group is produced following release of glyceraldehyde-3-phosphate from the indole-glycerol-3-phosphate.F) All of the above
G) A) and B)

Question 7

What are KFERQ proteins?
(I) Proteins that contain the KFERQ pentapeptide sequence (or a similar sequence) .
(II) Proteins that are selectively degraded in tissues that atrophy after a prolonged fast (starvation) .
(III) A special set of enzymes that are activated in response to starvation.

Accepted Answer

A)  I,II
B)  I,II,III
C)  II,III
D)  I,III
E)  I onlyF) A) and D)
G) B) and E)

Question 8

The total cost of nitrogen reduction is ____ and ___ transferred electrons.

Accepted Answer

A)  8 ATP;4
B)  12 ATP;8
C)  12 ATP;6
D)  16 ATP;8
E)  16 ATP;6F) None of the above
G) B) and D)

Question 9

Which enzyme catalyses a reaction via an enzyme-bound adenylated intermediate?

Accepted Answer

A)  glutamine synthetase
B)  argininosuccinate synthetase
C)  carbamoyl phosphate synthetase I
D)  Ac-CoA decarboxylase
E)  arginaseF) A) and B)
G) A) and C)

Question 10

The neurotransmitters,dopamine,epinephrine,and norepinephrine are synthesized from the amino acid

Accepted Answer

A)  tryptophan
B)  tyrosine
C)  glutamate
D)  aspartate
E)  lysineF) D) and E)
G) A) and B)

Question 11

What species are combined to produce carbamoyl phosphate?

Accepted Answer

A)  NH3 ,PO43−,HCO3−
B)  NH4+,PO43−,Ac-CoA,releasing CoA-SH
C)  glycine & inorganic phosphate,releasing CO2
D)  acetate & NH4+,releasing CO2
E)  alanine & inorganic phosphate,releasing acetateF) D) and E)
G) C) and E) A

Question 12

Matching
Choose the correct answer from the list.Not all the answers will be used.

-The cofactor ______ is used to transfer C1 units such as methyl,formyl,and methenyl groups.

Accepted Answer

A)   ribosomes
B)   jaundice
C)   channeling
D)   26S proteasome
E)   glutamine synthetaseF)  alanineG)  glutamateH)  vitamin B6I)  anammoxJ)  glutamine transferaseK)  THFL)  autotrophM)  vitamin DN)  lysosomesO)  diazotrophsP) F) and K)
Q) E) and J) K

Question 13

In which cellular location listed below does the following reaction take place?
Ornithine + carbamoyl-phosphate → citrulline

Accepted Answer

A)  cytosol
B)  mitochondrial matrix
C)  lysosome
D)  A or B
E)  none of the aboveF) A) and D)
G) None of the above

Question 14

Which of the following are essential amino acids for adult humans?

Accepted Answer

A)  Arg,His,Gly,Try
B)  Met,Lys,His,Val
C)  His,Leu,Tyr,Ala
D)  Met,Gly,Thr,Ser
E)  Ala,Arg,Cys,SerF) All of the above
G) A) and D)

Question 15

Individuals with an alanine to valine mutation in N5,N10 - methylenetetrahydrofolate reductase (MTHFR) 
(I) typically have higher levels of homocysteine.
(II) have increased risk for cardiovascular disease.
(III) typically have increased incidence of oxidative damage to the walls of blood vessels.
(IV) are at increased risk,if female,of giving birth to a child with a neural tube defect.

Accepted Answer

A)  I,II
B)  II,III
C)  I only
D)  IV only
E)  I,II,III,IVF) A) and E)
G) A) and D)

Question 16

In which cellular location listed below does the following reaction take place?
Arginine → urea + ornithine

Accepted Answer

A)  cytosol
B)  mitochondrial matrix
C)  lysosome
D)  A or B
E)  none of the aboveF) A) and B)
G) A) and C)

Question 17

Which of the following describes the steps required prior to ATP-dependent degradation of proteins?
(I) Ubiquitin is transferred to cysteine on a ubiquitin-conjugating enzyme.
(II) The protein is linked to at least four tandemly linked ubiquitin units.
(III) Activated ubiquitin is transferred to a lysine of the previously bound protein.
(IV) Ubiquitin is attached via a thioester to a unbiquitin-activiating enzyme.

Accepted Answer

A)  I,II,III,IV
B)  IV,I,III,II
C)  II,I,III,IV
D)  IV,II,I,III
E)  IV,II,III,IF) B) and E)
G) C) and D)

Question 18

Which of the following amino acids is NOT synthesized from aspartate?

Accepted Answer

A)  threonine
B)  methionine
C)  lysine
D)  cysteine
E)  All of the above are synthesized from aspartic acid.F) A) and E)
G) C) and E)

Question 19

The synthesis of which of the following uses an aminotransferase in the first step of the synthesis?

Accepted Answer

A)  glutamine
B)  proline
C)  serine
D)  valine
E)  all of the aboveF) A) and C)
G) A) and B)

Question 20

Matching
Choose the correct answer from the list.Not all the answers will be used.

-The amino acid ______ has been thought to act as a transfer system for NH3,safely allowing the toxic molecule to be transported from the liver to the kidneys.

Accepted Answer

A)   ribosomes
B)   jaundice
C)   channeling
D)   26S proteasome
E)   glutamine synthetaseF)  alanineG)  glutamateH)  vitamin B6I)  anammoxJ)  glutamine transferaseK)  THFL)  autotrophM)  vitamin DN)  lysosomesO)  diazotrophsP) E) and N)
Q) C) and M)

Exam 21: Amino Acid Metabolism

Heme biosynthesis

Correct Answer
verified

The pictured compound,glutamate-5-semialdehyde,is an intermediate in the biosynthesis of which of the following amino acids?

Correct Answer
verified

Matching Choose the correct answer from the list.Not all the answers will be used. -ATP-dependent degradation of ubiquitinated proteins is mediated by ______.

Correct Answer
verified

Matching Choose the correct answer from the list.Not all the answers will be used. -Aminotransferases utilize a coenzyme synthesized from ______.

Correct Answer
verified
H

Correct Answer
verified

Which of the following statements about tryptophan synthase is FALSE?

Correct Answer
verified

What are KFERQ proteins? (I) Proteins that contain the KFERQ pentapeptide sequence (or a similar sequence) . (II) Proteins that are selectively degraded in tissues that atrophy after a prolonged fast (starvation) . (III) A special set of enzymes that are activated in response to starvation.

Correct Answer
verified

The total cost of nitrogen reduction is __ and _ transferred electrons.

Correct Answer
verified

Which enzyme catalyses a reaction via an enzyme-bound adenylated intermediate?

Correct Answer
verified

The neurotransmitters,dopamine,epinephrine,and norepinephrine are synthesized from the amino acid

Correct Answer
verified

What species are combined to produce carbamoyl phosphate?

Correct Answer
verified
A

Matching Choose the correct answer from the list.Not all the answers will be used. -The cofactor ______ is used to transfer C₁ units such as methyl,formyl,and methenyl groups.

Correct Answer
verified
K

In which cellular location listed below does the following reaction take place? Ornithine + carbamoyl-phosphate → citrulline

Correct Answer
verified

Which of the following are essential amino acids for adult humans?

Correct Answer
verified

Correct Answer
verified

In which cellular location listed below does the following reaction take place? Arginine → urea + ornithine

Correct Answer
verified

Correct Answer
verified

Which of the following amino acids is NOT synthesized from aspartate?

Correct Answer
verified

The synthesis of which of the following uses an aminotransferase in the first step of the synthesis?

Correct Answer
verified

Matching Choose the correct answer from the list.Not all the answers will be used. -The amino acid ______ has been thought to act as a transfer system for NH₃,safely allowing the toxic molecule to be transported from the liver to the kidneys.

Correct Answer
verified

Exam 21: Amino Acid Metabolism

Heme biosynthesis

Correct AnswerverifiedShow Answer

The pictured compound,glutamate-5-semialdehyde,is an intermediate in the biosynthesis of which of the following amino acids?

Correct AnswerverifiedShow Answer

Matching Choose the correct answer from the list.Not all the answers will be used. -ATP-dependent degradation of ubiquitinated proteins is mediated by ______.

Correct AnswerverifiedShow Answer

Matching Choose the correct answer from the list.Not all the answers will be used. -Aminotransferases utilize a coenzyme synthesized from ______.

Correct AnswerverifiedH

Correct AnswerverifiedShow Answer

Which of the following statements about tryptophan synthase is FALSE?

Correct AnswerverifiedShow Answer

What are KFERQ proteins? (I) Proteins that contain the KFERQ pentapeptide sequence (or a similar sequence) . (II) Proteins that are selectively degraded in tissues that atrophy after a prolonged fast (starvation) . (III) A special set of enzymes that are activated in response to starvation.

Correct AnswerverifiedShow Answer

The total cost of nitrogen reduction is ____ and ___ transferred electrons.

Correct AnswerverifiedShow Answer

Which enzyme catalyses a reaction via an enzyme-bound adenylated intermediate?

Correct AnswerverifiedShow Answer

The neurotransmitters,dopamine,epinephrine,and norepinephrine are synthesized from the amino acid

Correct AnswerverifiedShow Answer

What species are combined to produce carbamoyl phosphate?

Correct AnswerverifiedA

Matching Choose the correct answer from the list.Not all the answers will be used. -The cofactor ______ is used to transfer C1 units such as methyl,formyl,and methenyl groups.

Correct AnswerverifiedK

In which cellular location listed below does the following reaction take place? Ornithine + carbamoyl-phosphate → citrulline

Correct AnswerverifiedShow Answer

Which of the following are essential amino acids for adult humans?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

In which cellular location listed below does the following reaction take place? Arginine → urea + ornithine

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which of the following amino acids is NOT synthesized from aspartate?

Correct AnswerverifiedShow Answer

The synthesis of which of the following uses an aminotransferase in the first step of the synthesis?

Correct AnswerverifiedShow Answer

Matching Choose the correct answer from the list.Not all the answers will be used. -The amino acid ______ has been thought to act as a transfer system for NH3,safely allowing the toxic molecule to be transported from the liver to the kidneys.

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
H

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

The total cost of nitrogen reduction is __ and _ transferred electrons.

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
A

Matching Choose the correct answer from the list.Not all the answers will be used. -The cofactor ______ is used to transfer C₁ units such as methyl,formyl,and methenyl groups.

Correct Answer
verified
K

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Matching Choose the correct answer from the list.Not all the answers will be used. -The amino acid ______ has been thought to act as a transfer system for NH₃,safely allowing the toxic molecule to be transported from the liver to the kidneys.

Correct Answer
verified