Question 1

The synthesis of methionine originates from which compound?

Accepted Answer

A)  $\alpha$-ketoglutarate 
B)  3-phosphoglycerate 
C)  oxaloacetate 
D)  pyruvate 
E)  ribose-5-phosphate 
A)  $\alpha$-ketoglutarate 
B)  3-phosphoglycerate 
C)  oxaloacetate 
D)  pyruvate 
E)  ribose-5-phosphate

Question 2

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 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. 
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.

Question 4

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

Accepted Answer

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

Question 5

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 6

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

Accepted Answer

A)  benzoic acid. 
B)  lactate. 
C)  orotate. 
D)  shikimate. 
E) $\alpha$-ketoglutarate. 
A)  benzoic acid. 
B)  lactate. 
C)  orotate. 
D)  shikimate. 
E) $\alpha$-ketoglutarate.

Question 7

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. 
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.

Question 8

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. 
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.

Question 9

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)  dinitrogenase 
A)  dinitrogenase reductase 
B)  nitrate reductase 
C)  nitrite reductase 
D)  nitrile reductase 
E)  dinitrogenase

Question 10

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 11

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

Question 12

Show the two-step reaction catalyzed by tryptophan synthetase.

Accepted Answer

Tryptophan synthetase is a key enzyme in

Question 13

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

Accepted Answer

The molecule you're referring to, @#LAT-DLM&-amino

Question 14

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

Accepted Answer

Glycine synthase catalyzes the reaction

Question 15

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

Accepted Answer

The intermediate of glycolysis that can

Question 16

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

Accepted Answer

A)  formate; glutamine; ammonia; glutamate 
B)  asparagine; glutamine; $\alpha$-ketoglutarate; glutamate 
C)  $\alpha$-ketoglutarate; glutamine; oxaloacetic acid; glutamate 
D)  $\alpha$-ketoglutarate; glutamine; $\alpha$-ketoglutarate; glutamate 
E)  glutamate; glutamine; $\alpha$-ketoglutarate; glutamate 
A)  formate; glutamine; ammonia; glutamate 
B)  asparagine; glutamine; $\alpha$-ketoglutarate; glutamate 
C)  $\alpha$-ketoglutarate; glutamine; oxaloacetic acid; glutamate 
D)  $\alpha$-ketoglutarate; glutamine; $\alpha$-ketoglutarate; glutamate 
E)  glutamate; glutamine; $\alpha$-ketoglutarate; glutamate

Question 17

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 18

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+ 
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+

Question 19

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

Question 20

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

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

The synthesis of methionine originates from which compound?

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?

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

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

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

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

Which statement is FALSE regarding glutamine synthetase?

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

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

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

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

Show the two-step reaction catalyzed by tryptophan synthetase.

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

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

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

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

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

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

The MOST direct precursors of the nitrogens of UMP are:

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

The Foundations of Biochemistry

Water

Amino Acids, Peptides, and Proteins

The Three-Dimensional Structure of Proteins

Protein Function

Enzymes

Carbohydrates and Glycobiology

Nucleotides and Nucleic Acids

DNA-Based Information Technologies

Lipids

Biological Membranes and Transport

Biosignaling

Bioenergetics and Biochemical Reaction Types

Glycolysis, Gluconeogenesis, and the Pentose Phosphate Pathway

Principles of Metabolic Regulation

The Citric Acid Cycle

Fatty Acid Catabolism

Amino Acid Oxidation and the Production of Urea

Oxidative Phosphorylation and Photophosphorylation

Carbohydrate Biosynthesis in Plants and Bacteria

Lipid Biosynthesis

Hormonal Regulation and Integration of Mammalian Metabolism

Genes and Chromosomes

DNA Metabolism

RNA Metabolism

Protein Metabolism

Regulation of Gene Expression

Filters

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?

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

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

Glutamine synthetase converts ___ to _, whereas glutamate synthase converts _ to ___.