Question 1

Draw the structure of 5'-IMP. Indicate with arrows those carbon atoms donated by derivatives of tetrahydrofolate and circle the atoms derived from glycine.

Accepted Answer

5'-IMP (5'-inosine monophosphate) is a n...

Question 2

Show how you can form $\delta$-aminolevulinate from either glycine and succinyl-CoA or from glutamate.

Accepted Answer

The molecule you're referring to, <img  loading="lazy" src="/assets/images/blured-textbook.svg" class="d-inline m-1" alt="blured image" width="139" height="30">-amino...

Question 3

Which statement is TRUE regarding the conversion of UTP into CTP by cytidylate synthetase?

Accepted Answer

A)   Glutamate is also a substrate for this reaction.
B)   This reaction consumes one phosphoanhydride bond.
C)   This enzyme is an isomerase.
D)   Ammonia is a substrate for the overall reaction.
E)   Folate is a required cofactor for the reaction.F) A) and D)
G) A) and E)

Question 4

Which list CORRECTLY arranges nitrogen-containing species from most to least oxidized?

Accepted Answer

A)   NO3- > NO2- > NH4+ > N2
B)   NO3- > NO2- > N2 > NH4+
C)   NO2- > NO3- > NH4+ > N2
D)   N2 > NO2- > NO3- > NH4+
E)   NO2- > NO3- > N2 > NH4+F) B) and D)
G) B) and E)

Question 5

The MOST direct precursors of the nitrogens of UMP are:

Accepted Answer

A)   aspartate and carbamoyl phosphate.
B)   glutamate and aspartate.
C)   glutamate and carbamoyl phosphate.
D)   glutamine and aspartate.
E)   glutamine and carbamoyl phosphate.F) B) and D)
G) B) and C)

Question 6

Which enzyme is NOT involved in the assimilation of inorganic nitrogen into an organic molecule?

Accepted Answer

A)   dinitrogenase reductase
B)   nitrate reductase
C)   nitrite reductase
D)   nitrile reductase
E)   dinitrogenaseF) A) and D)
G) D) and E)

Question 7

Show the reaction catalyzed by glycine synthase, indicating the role of any cofactors that participate.

Accepted Answer

Glycine synthase catalyzes the reaction ...

Question 8

Show the two-step reaction catalyzed by tryptophan synthetase.

Accepted Answer

Tryptophan synthetase is a key enzyme in...

Question 9

The synthesis of methionine originates from which compound?

Accepted Answer

A)    α\alphaα -ketoglutarate
B)   3-phosphoglycerate
C)   oxaloacetate
D)   pyruvate
E)   ribose-5-phosphate F) B) and C)
G) B) and E)

Question 10

Glutamine synthetase converts _____ to _____, whereas glutamate synthase converts _____ to _____.

Accepted Answer

A)   formate; glutamine; ammonia; glutamate
B)   asparagine; glutamine;  α\alphaα -ketoglutarate; glutamate
C)    α\alphaα -ketoglutarate; glutamine; oxaloacetic acid; glutamate
D)    α\alphaα -ketoglutarate; glutamine;  α\alphaα -ketoglutarate; glutamate
E)   glutamate; glutamine;  α\alphaα -ketoglutarate; glutamate F) B) and D)
G) A) and C)

Question 11

Draw the structure of 5'-UMP (uridylic acid). Circle those carbon atoms donated by atoms derived from aspartate.

Accepted Answer

5'-UMP, or 5'-uridine monophosphate, is ...

Question 12

If acetyl-CoA containing radiolabeled carbons in the acetyl group was used to synthesize arginine, where would the radioactive carbons be found?

Accepted Answer

To determine where the radiolabeled carb...

Question 13

Which statement is FALSE regarding glutamine synthetase?

Accepted Answer

A)   Both the Type I and Type II forms have dihedral symmetry.
B)   Histidine, glycine, and alanine are all negative effectors for this enzyme.
C)   It is regulated by multiple feedback inhibitors and covalent modification.
D)   ATP is an inhibitor for this enzyme.
E)   This enzyme is classified as a ligase.F) A) and C)
G) A) and E)

Question 14

Which statement is TRUE of the biosynthetic pathway for purine nucleotides?

Accepted Answer

A)   CO2 does not participate in any of the steps in this pathway.
B)   Deoxyribonucleotides are formed from 5-phosphodeoxyribosyl 1-pyrophosphate.
C)   Inosinate is the purine nucleotide that is the precursor of both adenylate and guanylate.
D)   Orotic acid is an essential precursor for purine nucleotides.
E)   The amino acid valine is one of the precursors contributing to purine nucleotides.F) B) and C)
G) B) and D)

Question 15

Reduction of nitrogen (N2) to ammonia (NH3) is energetically favorable. Why do nitrogen-fixing bacteria require a substantial amount of ATP to make this process proceed?

Accepted Answer

The reduction of nitrogen (N₂) to ammoni...

Question 16

Show the steps by which an intermediate of glycolysis can be converted into serine.

Accepted Answer

The intermediate of glycolysis that can ...

Question 17

Which kind of reversible covalent modification is used to regulate glutamine synthetase?

Accepted Answer

A)   ADP-ribosylation
B)   adenylylation
C)   phosphorylation
D)   acetylation
E)   both ADP-ribosylation and adenylylationF) A) and B)
G) B) and E)

Question 18

The ribosyl phosphate moiety needed for the synthesis of orotidylate, inosinate, and guanylate is provided MOST directly by:

Accepted Answer

A)   5-phosphoribosyl 1-pyrophosphate.
B)   adenosine 5'-phosphate.
C)   guanosine 5'-phosphate.
D)   ribose 5-phosphate.
E)   ribulose 5-phosphate.F) A) and E)
G) A) and B)

Question 19

An important intermediate in the biosynthetic pathway to aromatic amino acids is:

Accepted Answer

A)   benzoic acid.
B)   lactate.
C)   orotate.
D)   shikimate.
E)   α\alphaα -ketoglutarate. F) C) and E)
G) B) and C)

Question 20

An amino acid that does NOT derive its carbon skeleton, at least in part, from  α\alphaα -ketoglutarate is:

Accepted Answer

A)   arginine.
B)   glutamate.
C)   glutamine.
D)   proline.
E)   threonine. F) A) and B)
G) B) and D)

Exam 22: Biosynthesis of Amino Acids, Nucleotides, and Related Molecules

An amino acid that does NOT derive its carbon skeleton, at least in part, from α\alphaα -ketoglutarate is:

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Show how you can form δ\deltaδ -aminolevulinate from either glycine and succinyl-CoA or from glutamate.

Correct AnswerAnswered by ExamLex AIThe molecule you're referring to, -amino...View AnswerShow Answer

Show the steps by which an intermediate of glycolysis can be converted into serine.

Correct AnswerAnswered by ExamLex AIThe intermediate of glycolysis that can ...View AnswerShow Answer

Which statement is FALSE regarding glutamine synthetase?

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An important intermediate in the biosynthetic pathway to aromatic amino acids is:

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Which list CORRECTLY arranges nitrogen-containing species from most to least oxidized?

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The synthesis of methionine originates from which compound?

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Which statement is TRUE of the biosynthetic pathway for purine nucleotides?

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Reduction of nitrogen (N2) to ammonia (NH3) is energetically favorable. Why do nitrogen-fixing bacteria require a substantial amount of ATP to make this process proceed?

Correct AnswerAnswered by ExamLex AIThe reduction of nitrogen (N₂) to ammoni...View AnswerShow Answer

The MOST direct precursors of the nitrogens of UMP are:

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Draw the structure of 5'-IMP. Indicate with arrows those carbon atoms donated by derivatives of tetrahydrofolate and circle the atoms derived from glycine.

Correct AnswerAnswered by ExamLex AI5'-IMP (5'-inosine monophosphate) is a n...View AnswerShow Answer

Which statement is TRUE regarding the conversion of UTP into CTP by cytidylate synthetase?

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If acetyl-CoA containing radiolabeled carbons in the acetyl group was used to synthesize arginine, where would the radioactive carbons be found?

Correct AnswerAnswered by ExamLex AITo determine where the radiolabeled carb...View AnswerShow Answer

Show the reaction catalyzed by glycine synthase, indicating the role of any cofactors that participate.

Correct AnswerAnswered by ExamLex AIGlycine synthase catalyzes the reaction ...View AnswerShow Answer

The ribosyl phosphate moiety needed for the synthesis of orotidylate, inosinate, and guanylate is provided MOST directly by:

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Draw the structure of 5'-UMP (uridylic acid). Circle those carbon atoms donated by atoms derived from aspartate.

Correct AnswerAnswered by ExamLex AI5'-UMP, or 5'-uridine monophosphate, is ...View AnswerShow Answer

Which enzyme is NOT involved in the assimilation of inorganic nitrogen into an organic molecule?

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Show the two-step reaction catalyzed by tryptophan synthetase.

Correct AnswerAnswered by ExamLex AITryptophan synthetase is a key enzyme in...View AnswerShow Answer

Which kind of reversible covalent modification is used to regulate glutamine synthetase?

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Glutamine synthetase converts _____ to _____, whereas glutamate synthase converts _____ to _____.

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An amino acid that does NOT derive its carbon skeleton, at least in part, from $\alpha$ -ketoglutarate is:

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Show how you can form $\delta$ -aminolevulinate from either glycine and succinyl-CoA or from glutamate.

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The molecule you're referring to, -amino...
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The intermediate of glycolysis that can ...
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Reduction of nitrogen (N₂) to ammonia (NH₃) is energetically favorable. Why do nitrogen-fixing bacteria require a substantial amount of ATP to make this process proceed?

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The reduction of nitrogen (N₂) to ammoni...
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5'-IMP (5'-inosine monophosphate) is a n...
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To determine where the radiolabeled carb...
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Glycine synthase catalyzes the reaction ...
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5'-UMP, or 5'-uridine monophosphate, is ...
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Tryptophan synthetase is a key enzyme in...
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Glutamine synthetase converts ___ to _, whereas glutamate synthase converts _ to ___.

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