Question 1

The enzymatic machinery to fix atmospheric N2 into NH4+ is:

Accepted Answer

A)  a means of producing ATP when excess N2 is available.
B)  composed of two key proteins,each containing iron.
C)  relatively stable when exposed to O2.
D)  specific to plant cells.
E)  unaffected by the supply of electrons.F) A) and E)
G) None of the above

Question 2

Which one of the following statements correctly describes the biosynthetic pathway for purine nucleotides?

Accepted Answer

A)  Purine deoxynucleotides are made by the same path as ribonucleotides,followed by reduction of the ribose moiety.
B)  The first enzyme in the path is aspartate transcarbamoylase (ATCase) .
C)  The nitrogen in the purine base that is bonded to ribose in the nucleotide is derived originally from glycine.
D)  The pathway occurs only in plants and bacteria,not in animals.
E)  The purine rings are first synthesized,then condensed with ribose phosphate.F) C) and E)
G) A) and C)

Question 3

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.F) A) and E)
G) A) and C)

Question 4

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

Accepted Answer

The structure of UMP is shown in ,which ...

Question 5

Glutamine is a nitrogen donor in the synthesis of:

Accepted Answer

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

Question 6

The plant hormone indole-3-acetate (auxin) is formed from:

Accepted Answer

A)  arginine.
B)  histidine.
C)  phenylalanine.
D)  threonine.
E)  tryptophan.F) A) and E)
G) None of the above

Question 7

A cell that is unable to synthesize or obtain tetrahydrofolic acid (H4 folate) would probably be deficient in the biosynthesis of:

Accepted Answer

A)  CMP.
B)  GMP.
C)  orotate.
D)  thymidylate (TMP) .
E)  UMP.F) A) and B)
G) A) and E)

Question 8

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) A) and E)
G) C) and E)

Question 9

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

Accepted Answer

Serine is derived from 3-phosp...

Question 10

Match the signaling molecule with its amino acid precursor (a given precursor may be used more than once or not at all):
-

Accepted Answer

(a)-(4);
(b)-(3);
...

Question 11

Glutamine,arginine,and proline:

Accepted Answer

A)  do not have a common precursor.
B)  may all be derived from a citric acid cycle intermediate.
C)  may all be derived from a Cori cycle intermediate.
D)  may all be derived from a glycolytic intermediate.
E)  may all be derived from a urea cycle intermediate.F) C) and D)
G) A) and C)

Question 12

Describe two types of regulation of the enzyme glutamine synthetase and explain why the regulation of this enzyme is so complex.

Accepted Answer

(1)The enzyme is subject to cumulative a...

Question 13

If glucose labeled with 14C at C-1 were the starting material for amino acid biosynthesis,the product(s) that would be readily formed is (are) :

Accepted Answer

A)  serine labeled at the carboxyl carbon.
B)  serine labeled at alpha carbon.
C)  serine labeled at the R-group carbon.
D)  All of the above
E)  None of the aboveF) B) and C)
G) A) and E)

Question 14

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

Accepted Answer

In most animals,glycine and succinyl-CoA...

Question 15

In bacteria,the amino acids listed below can be derived directly or indirectly from serine,alanine,aspartate,glutamate,or chorismate.Indicate below which of these "parent" compounds provides the carbon skeleton for each amino acid:
Parent compound
Asparagine __________________
Tryptophan __________________
Glycine __________________
Methionine __________________
Threonine __________________
Cysteine __________________
Proline __________________
Isoleucine __________________
Phenylalanine __________________

Accepted Answer

Aspartate (asparagine)
chorismate (trypt...

Question 16

The nitrogen atom in the side chain of lysine is derived from which amino acid?

Accepted Answer

A)  Aspartic acid
B)  Glutamic acid
C)  Glutamine
D)  Asparagine
E)  ArginineF) B) and C)
G) C) and E)

Question 17

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.F) B) and E)
G) C) and D)

Question 18

An animal cell is capable of converting alanine into serine.What is the shortest pathway using known enzymes by which this conversion could be accomplished? Show intermediates and cofactors;no enzyme names are required.(Hint: The first step is removal of the nitrogen by transamination. )

Accepted Answer

(1)Alanine

pyruvate
(2)Pyruvate + HCO

Question 19

Diagram the biosynthetic pathway from UMP to dTTP.Use abbreviations (e.g. ,UMP),not complete structures,and indicate where any co-substrates participate.

Accepted Answer

UMP + ATP <img  loading="lazy" src="/assets/images/blured-textbook.svg" class="d-inline m-1" alt="blured image" width="139" height="30"> UDP + ADP (nucleoside monopho...

Question 20

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

Accepted Answer

-Ketoglutarate + NH₄

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

If glucose labeled with ¹⁴C at C-1 were the starting material for amino acid biosynthesis,the product(s) that would be readily formed is (are) :

Correct Answer
verified

Which one of the following statements correctly describes the biosynthetic pathway for purine nucleotides?

Correct Answer
verified

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

Correct Answer
verified
Serine is derived from 3-phosp...
View Answer

Homoserine is:

Correct Answer
verified

Glutamine,arginine,and proline:

Correct Answer
verified

The plant hormone indole-3-acetate (auxin) is formed from:

Correct Answer
verified

Correct Answer
verified
Aspartate (asparagine)
chorismate (trypt...
View Answer

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

Correct Answer
verified
The structure of UMP is shown in ,which ...
View Answer

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

Correct Answer
verified
In most animals,glycine and succinyl-CoA...
View Answer

The enzymatic machinery to fix atmospheric N₂ into NH₄⁺ is:

Correct Answer
verified

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

Correct Answer
verified

Diagram the biosynthetic pathway from UMP to dTTP.Use abbreviations (e.g. ,UMP),not complete structures,and indicate where any co-substrates participate.

Correct Answer
verified
UMP + ATP UDP + ADP (nucleoside monopho...
View Answer

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

Correct Answer
verified
-Ketoglutarate + NH_{4View Answer}

An animal cell is capable of converting alanine into serine.What is the shortest pathway using known enzymes by which this conversion could be accomplished? Show intermediates and cofactors;no enzyme names are required.(Hint: The first step is removal of the nitrogen by transamination. )

Correct Answer
verified
(1)Alanine pyruvate
(2)Pyruvate + HCO
View Answer

Describe two types of regulation of the enzyme glutamine synthetase and explain why the regulation of this enzyme is so complex.

Correct Answer
verified
(1)The enzyme is subject to cumulative a...
View Answer

A cell that is unable to synthesize or obtain tetrahydrofolic acid (H₄ folate) would probably be deficient in the biosynthesis of:

Correct Answer
verified

The nitrogen atom in the side chain of lysine is derived from which amino acid?

Correct Answer
verified

Glutamine is a nitrogen donor in the synthesis of:

Correct Answer
verified

Match the signaling molecule with its amino acid precursor (a given precursor may be used more than once or not at all): -

Correct Answer
verified
(a)-(4);
(b)-(3);
...
View Answer

The synthesis of purine and pyrimidine nucleotides differ in that:

Correct Answer
verified

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

If glucose labeled with 14C at C-1 were the starting material for amino acid biosynthesis,the product(s) that would be readily formed is (are) :

Correct AnswerverifiedShow Answer

Which one of the following statements correctly describes the biosynthetic pathway for purine nucleotides?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedSerine is derived from 3-phosp...View AnswerShow Answer

Homoserine is:

Correct AnswerverifiedShow Answer

Glutamine,arginine,and proline:

Correct AnswerverifiedShow Answer

The plant hormone indole-3-acetate (auxin) is formed from:

Correct AnswerverifiedShow Answer

Correct AnswerverifiedAspartate (asparagine)chorismate (trypt...View AnswerShow Answer

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

Correct AnswerverifiedThe structure of UMP is shown in ,which ...View AnswerShow Answer

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

Correct AnswerverifiedIn most animals,glycine and succinyl-CoA...View AnswerShow Answer

The enzymatic machinery to fix atmospheric N2 into NH4+ is:

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Diagram the biosynthetic pathway from UMP to dTTP.Use abbreviations (e.g. ,UMP),not complete structures,and indicate where any co-substrates participate.

Correct AnswerverifiedUMP + ATP UDP + ADP (nucleoside monopho...View AnswerShow Answer

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

Correct Answerverified-Ketoglutarate + NH4View AnswerShow Answer

An animal cell is capable of converting alanine into serine.What is the shortest pathway using known enzymes by which this conversion could be accomplished? Show intermediates and cofactors;no enzyme names are required.(Hint: The first step is removal of the nitrogen by transamination. )

Correct Answerverified(1)Alanine pyruvate(2)Pyruvate + HCOView AnswerShow Answer

Describe two types of regulation of the enzyme glutamine synthetase and explain why the regulation of this enzyme is so complex.

Correct Answerverified(1)The enzyme is subject to cumulative a...View AnswerShow Answer

A cell that is unable to synthesize or obtain tetrahydrofolic acid (H4 folate) would probably be deficient in the biosynthesis of:

Correct AnswerverifiedShow Answer

The nitrogen atom in the side chain of lysine is derived from which amino acid?

Correct AnswerverifiedShow Answer

Glutamine is a nitrogen donor in the synthesis of:

Correct AnswerverifiedShow Answer

Match the signaling molecule with its amino acid precursor (a given precursor may be used more than once or not at all): -

Correct Answerverified(a)-(4); (b)-(3); ...View AnswerShow Answer

The synthesis of purine and pyrimidine nucleotides differ in that:

Correct AnswerverifiedShow Answer

If glucose labeled with ¹⁴C at C-1 were the starting material for amino acid biosynthesis,the product(s) that would be readily formed is (are) :

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Serine is derived from 3-phosp...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Aspartate (asparagine)
chorismate (trypt...
View Answer

Correct Answer
verified
The structure of UMP is shown in ,which ...
View Answer

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

Correct Answer
verified
In most animals,glycine and succinyl-CoA...
View Answer

The enzymatic machinery to fix atmospheric N₂ into NH₄⁺ is:

Correct Answer
verified

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

Correct Answer
verified

Correct Answer
verified
UMP + ATP UDP + ADP (nucleoside monopho...
View Answer

Correct Answer
verified
-Ketoglutarate + NH_{4View Answer}

Correct Answer
verified
(1)Alanine pyruvate
(2)Pyruvate + HCO
View Answer

Correct Answer
verified
(1)The enzyme is subject to cumulative a...
View Answer

A cell that is unable to synthesize or obtain tetrahydrofolic acid (H₄ folate) would probably be deficient in the biosynthesis of:

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
(a)-(4);
(b)-(3);
...
View Answer

Correct Answer
verified