Question 1

The amino acid _____ and is an intermediate in the biosynthesis of _____.

Accepted Answer

A)  histidine; purines 
B)  glycine; heme 
C)  serine; heme 
D)  serine; sphingosine 
E)  glutamine; glutathione 
A)  histidine; purines 
B)  glycine; heme 
C)  serine; heme 
D)  serine; sphingosine 
E)  glutamine; glutathione

Question 2

An intermediate of purine degradation in humans is:

Accepted Answer

A)  glutamate. 
B)  NH4+. 
C)  succinate. 
D)  urea. 
E)  uric acid. 
A)  glutamate. 
B)  NH4+. 
C)  succinate. 
D)  urea. 
E)  uric acid.

Question 3

If a cell were unable to synthesize or obtain tetrahydrofolic acid (H4 folate), it would probably be deficient in the biosynthesis of:

Accepted Answer

A)  isoleucine. 
B)  leucine. 
C)  lysine. 
D)  methionine. 
E)  serine. 
A)  isoleucine. 
B)  leucine. 
C)  lysine. 
D)  methionine. 
E)  serine.

Question 4

Which statement is TRUE about gout?

Accepted Answer

A)  Gout is caused by excessive breakdown of pyrimidine nucleotides. 
B)  Gout can be treated by administration of fluorouracil. 
C)  Gout is particularly prevalent in patients lacking xanthine oxidase. 
D)  Gout leads to deposition of sodium urate crystals in the joints. 
E)  Eating more liver is an effective way to treat the symptoms of gout. 
A)  Gout is caused by excessive breakdown of pyrimidine nucleotides. 
B)  Gout can be treated by administration of fluorouracil. 
C)  Gout is particularly prevalent in patients lacking xanthine oxidase. 
D)  Gout leads to deposition of sodium urate crystals in the joints. 
E)  Eating more liver is an effective way to treat the symptoms of gout.

Question 5

Give the overall reaction that results from the combined action of glutamate synthase and glutamine synthetase.

Accepted Answer

Glutamate synthase and glutamine synthet

Question 6

The synthesis of purine and pyrimidine nucleotides differ in that:

Accepted Answer

A)  ATP is required in the synthesis of purines but not in the synthesis of pyrimidines. 
B)  purine biosynthesis starts with the formation of PRPP, whereas pyrimidines incorporate the PRPP near the end of the pathway. 
C)  purine formation requires a THF derivative, whereas pyrimidine formation does not. 
D)  pyrimidine biosynthesis is tightly regulated in the cell, whereas purine biosynthesis is not. 
E)  pyrimidines go through many steps, adding a single carbon or nitrogen each time, whereas the basic skeleton for purines is formed by two main precursors. 
A)  ATP is required in the synthesis of purines but not in the synthesis of pyrimidines. 
B)  purine biosynthesis starts with the formation of PRPP, whereas pyrimidines incorporate the PRPP near the end of the pathway. 
C)  purine formation requires a THF derivative, whereas pyrimidine formation does not. 
D)  pyrimidine biosynthesis is tightly regulated in the cell, whereas purine biosynthesis is not. 
E)  pyrimidines go through many steps, adding a single carbon or nitrogen each time, whereas the basic skeleton for purines is formed by two main precursors.

Question 7

Draw the structure of 5'AMP. What is the first "committed" step in the biosynthetic sequence that leads to 5'AMP? How is this step regulated?

Accepted Answer

5'AMP, or 5' adenosine monophosphate, is

Question 8

Homoserine is:

Accepted Answer

A)  a precursor of both methionine and threonine. 
B)  a precursor of serine. 
C)  derived from homocysteine. 
D)  derived from serine. 
E)  derived from threonine. 
A)  a precursor of both methionine and threonine. 
B)  a precursor of serine. 
C)  derived from homocysteine. 
D)  derived from serine. 
E)  derived from threonine.

Question 9

Draw the structure of deoxythymidylic acid (dTMP). Indicate the source of each N and each C in the thymine ring, including its substituents.

Accepted Answer

Deoxythymidylic acid (dTMP) is a nucleot

Question 10

Trace the path of nitrogen from atmospheric N2 into glutamate. Name the intermediates (no structures necessary) and enzymes, and show any coenzymes involved.

Accepted Answer

The path of nitrogen from atmospheric N

Question 11

L-Dopa is an intermediate in the conversion of:

Accepted Answer

A)  phenylalanine to homogentisic acid. 
B)  phenylalanine to tyrosine. 
C)  tyrosine to epinephrine. 
D)  tyrosine to phenylalanine. 
E)  tyrosine to phenylpyruvate. 
A)  phenylalanine to homogentisic acid. 
B)  phenylalanine to tyrosine. 
C)  tyrosine to epinephrine. 
D)  tyrosine to phenylalanine. 
E)  tyrosine to phenylpyruvate.

Question 12

Describe the pathway by which GMP is converted into GTP; show the co-substrates that are involved and name the enzymes.

Accepted Answer

The conversion of GMP (guanosine monopho

Question 13

Which statement is NOT true about the anammox reaction?

Accepted Answer

A)  Anammox converts ammonia to nitrogen. 
B)  Anammox is performed by symbiotic bacteria of leguminous plants. 
C)  Anammox generates the highly reactive molecule hydrazine that is a component of rocket fuel. 
D)  Anammox occursw anaerobically. 
E)  The ultimate electron acceptor in anammox is nitrite. 
A)  Anammox converts ammonia to nitrogen. 
B)  Anammox is performed by symbiotic bacteria of leguminous plants. 
C)  Anammox generates the highly reactive molecule hydrazine that is a component of rocket fuel. 
D)  Anammox occursw anaerobically. 
E)  The ultimate electron acceptor in anammox is nitrite.

Question 14

Show the reaction catalyzed by thymidylate synthase and explain with a simple diagram how the chemotherapeutic agents fluorouracil and methotrexate inhibit the synthesis of dTMP.

Accepted Answer

Thymidylate synthase is an enzyme that c

Question 15

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

Accepted Answer

Leucine is an essential amino acid that

Question 16

An amino acid that does NOT derive its carbon skeleton, at least in part, from oxaloacetate is:

Accepted Answer

A)  aspartate. 
B)  lysine. 
C)  methionine. 
D)  proline. 
E)  threonine. 
A)  aspartate. 
B)  lysine. 
C)  methionine. 
D)  proline. 
E)  threonine.

Question 17

Glutamine is a nitrogen donor in the synthesis of:

Accepted Answer

A)  CTP. 
B)  dTTP. 
C)  inosinic acid (IMP). 
D)  orotate. 
E)  UMP. 
A)  CTP. 
B)  dTTP. 
C)  inosinic acid (IMP). 
D)  orotate. 
E)  UMP.

Question 18

What high-energy structure is found as part of the major intermediate in the glutamine synthetase reaction?

Accepted Answer

A)  a phosphoanhydride bond 
B)  a phosphoester 
C)  an acyl phosphate 
D)  an enol 
E)  a thioester 
A)  a phosphoanhydride bond 
B)  a phosphoester 
C)  an acyl phosphate 
D)  an enol 
E)  a thioester

Question 19

Phosphocreatine is derived from which amino acid?

Accepted Answer

A)  alanine 
B)  arginine 
C)  cysteine 
D)  serine 
E)  lysine 
A)  alanine 
B)  arginine 
C)  cysteine 
D)  serine 
E)  lysine

Question 20

Which molecule does NOT require 5-phosphoribosyl-1-pyrophosphate (PRPP) as a substrate for biosynthesis?

Accepted Answer

A)  adenosine monophosphate 
B)  cytidine monophosphate 
C)  guanosine monophosphate 
D)  histidine 
E)  All of these molecules require PRPP for biosynthetic pathways. 
A)  adenosine monophosphate 
B)  cytidine monophosphate 
C)  guanosine monophosphate 
D)  histidine 
E)  All of these molecules require PRPP for biosynthetic pathways.

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

The amino acid _____ and is an intermediate in the biosynthesis of _____.

An intermediate of purine degradation in humans is:

If a cell were unable to synthesize or obtain tetrahydrofolic acid (H4 folate), it would probably be deficient in the biosynthesis of:

Which statement is TRUE about gout?

Give the overall reaction that results from the combined action of glutamate synthase and glutamine synthetase.

The synthesis of purine and pyrimidine nucleotides differ in that:

Draw the structure of 5'AMP. What is the first "committed" step in the biosynthetic sequence that leads to 5'AMP? How is this step regulated?

Homoserine is:

Draw the structure of deoxythymidylic acid (dTMP). Indicate the source of each N and each C in the thymine ring, including its substituents.

Trace the path of nitrogen from atmospheric N2 into glutamate. Name the intermediates (no structures necessary) and enzymes, and show any coenzymes involved.

L-Dopa is an intermediate in the conversion of:

Describe the pathway by which GMP is converted into GTP; show the co-substrates that are involved and name the enzymes.

Which statement is NOT true about the anammox reaction?

Show the reaction catalyzed by thymidylate synthase and explain with a simple diagram how the chemotherapeutic agents fluorouracil and methotrexate inhibit the synthesis of dTMP.

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

An amino acid that does NOT derive its carbon skeleton, at least in part, from oxaloacetate is:

Glutamine is a nitrogen donor in the synthesis of:

What high-energy structure is found as part of the major intermediate in the glutamine synthetase reaction?

Phosphocreatine is derived from which amino acid?

Which molecule does NOT require 5-phosphoribosyl-1-pyrophosphate (PRPP) as a substrate for biosynthesis?

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

The amino acid _ and is an intermediate in the biosynthesis of _.

If a cell were unable to synthesize or obtain tetrahydrofolic acid (H₄ folate), it would probably be deficient in the biosynthesis of:

Trace the path of nitrogen from atmospheric N₂ into glutamate. Name the intermediates (no structures necessary) and enzymes, and show any coenzymes involved.