Question 1

Which of the following is a versatile carrier of several different one-carbon units?

Accepted Answer

A)   pyridoxal phosphate
B)   biotin
C)   tetrahydrofolate
D)   coenzyme A
E)   None of the answers is correct.F) A) and B)
G) A) and E) C

Question 2

Chorismate is a precursor to the amino acids

Accepted Answer

A)   tryptophan, tyrosine, and phenylalanine.
B)   serine, glycine and cysteine.
C)   isoleucine, leucine and valine.
D)   methionine, threonine, and lysine.
E)   None of the answers is correct.F) A) and E)
G) D) and E)

Question 3

What molecule is an activated form of ribose phosphate and a precursor for histidine?

Accepted Answer

A)   ribose triphosphate
B)   PRPP (5-phosphoribosyl-1-pyrophosphate) 
C)   ATP
D)   cyclic AMP
E)   None of the answers is correct.F) C) and D)
G) A) and B)

Question 4

What unusual (and not recommended)experiments were carried out by Shemin and colleagues?

Accepted Answer

Acting as a human guinea pig,S...

Question 5

Essential amino acids (for humans) differ from nonessential amino acids in that

Accepted Answer

A)   nonessential amino acids are synthesized in simple reaction pathways compared to complex pathways for most essential amino acids.
B)   essential amino acids are generally synthesized directly from citric acid cycle intermediates, but not nonessential amino acids.
C)   microorganisms and animals cannot synthesize essential amino acids but plants can.
D)   animals cannot synthesize essential amino acids because they have lost the ability to carry out transamination reactions.
E)   All of the answers are correct.F) C) and D)
G) D) and E) A

Question 6

This amino acid,in high levels,is correlated with the damage of cells lining the blood vessels.

Accepted Answer

A)   serine
B)   cysteine
C)   S-adenosylmethionine
D)   citrulline
E)   homocysteineF) B) and E)
G) All of the above

Question 7

The carbon skeletons used to synthesize amino acids are intermediates found in

Accepted Answer

A)   glycolysis.
B)   glycogen metabolism.
C)   citric acid cycle.
D)   All the answers are correct.
E)   glycolysis and citric acid cycleF) C) and D)
G) A) and B) E

Question 8

How does the herbicide glyphosate work?

Accepted Answer

Glyphosate (Roundup is one brand)acts by...

Question 9

What is the activated methyl cycle?

Accepted Answer

The methyl group on the side-chain of me...

Question 10

How may have feedback inhibition processes evolved?

Accepted Answer

A)   duplication of genes encoding catalytic domains
B)   evolution of homologous subunits in the enzyme catalyzing the committed step
C)   linking specific regulatory domains to catalytic domains
D)   linking of multiple regulatory domains to one another
E)   All of the answers are correct.F) A) and B)
G) A) and C)

Question 11

What do S-adenosylmethionine and fruit ripening have in common?

Accepted Answer

S-Adenosylmethionine is a prec...

Question 12

Which of the following is the original nitrogen source for the nitrogen found in amino acids?

Accepted Answer

A)   atmospheric nitrogen (N2) 
B)   tetrahydrofolate
C)   glutamine
D)   ammonia (NH3) 
E)   ureaF) B) and E)
G) A) and D)

Question 13

Describe the structure and function of the FeMo cofactor.

Accepted Answer

This unusual redox center is the site of...

Question 14

What process converts N2 to NH3?

Accepted Answer

A)   urea cycle
B)   glutamine hydrolysis
C)   denitrification
D)   nitrogen fixation
E)   None of the answers is correct.F) A) and E)
G) B) and D)

Question 15

Describe the process and proteins involved in nitrogen fixation.

Accepted Answer

Electrons are provided by ferredoxin,tra...

Question 16

What amino acid is added to indole in the biosynthesis of tryptophan?

Accepted Answer

A)   glutamine
B)   serine
C)   tyrosine
D)   alanine
E)   None of the answers is correct.F) B) and E)
G) A) and C)

Question 17

An example of a reaction controlled by enzyme multiplicity is

Accepted Answer

A)   phosphorylation of asparagine by aspartokinases.
B)   phosphorylation of aspartate by aspartokinases.
C)   phosphorylation of glutamine by glutamine synthetase.
D)   all of the above.
E)   None of the answers is correct.F) B) and C)
G) A) and B)

Question 18

Which of the following is a vasodilator that is derived from histidine?

Accepted Answer

A)   epinephrine
B)   norepinephrine
C)   histamine
D)   adenosine
E)   prostacyclinF) D) and E)
G) A) and E)

Question 19

What is catalytic substrate channeling?

Accepted Answer

Channeling increases the catalytic rate,...

Question 20

Amino acid synthesis is primarily regulated by

Accepted Answer

A)   turnover.
B)   diet.
C)   urea excretion.
D)   allosteric enzyme regulation.
E)   All the answers are correct.F) B) and D)
G) All of the above

Exam 24: The Biosynthesis of Amino Acids

Which of the following is a versatile carrier of several different one-carbon units?

Correct AnswerverifiedC

Chorismate is a precursor to the amino acids

Correct AnswerverifiedShow Answer

What molecule is an activated form of ribose phosphate and a precursor for histidine?

Correct AnswerverifiedShow Answer

What unusual (and not recommended)experiments were carried out by Shemin and colleagues?

Correct AnswerverifiedActing as a human guinea pig,S...View AnswerShow Answer

Essential amino acids (for humans) differ from nonessential amino acids in that

Correct AnswerverifiedA

This amino acid,in high levels,is correlated with the damage of cells lining the blood vessels.

Correct AnswerverifiedShow Answer

The carbon skeletons used to synthesize amino acids are intermediates found in

Correct AnswerverifiedE

How does the herbicide glyphosate work?

Correct AnswerverifiedGlyphosate (Roundup is one brand)acts by...View AnswerShow Answer

What is the activated methyl cycle?

Correct AnswerverifiedThe methyl group on the side-chain of me...View AnswerShow Answer

How may have feedback inhibition processes evolved?

Correct AnswerverifiedShow Answer

What do S-adenosylmethionine and fruit ripening have in common?

Correct AnswerverifiedS-Adenosylmethionine is a prec...View AnswerShow Answer

Which of the following is the original nitrogen source for the nitrogen found in amino acids?

Correct AnswerverifiedShow Answer

Describe the structure and function of the FeMo cofactor.

Correct AnswerverifiedThis unusual redox center is the site of...View AnswerShow Answer

What process converts N2 to NH3?

Correct AnswerverifiedShow Answer

Describe the process and proteins involved in nitrogen fixation.

Correct AnswerverifiedElectrons are provided by ferredoxin,tra...View AnswerShow Answer

What amino acid is added to indole in the biosynthesis of tryptophan?

Correct AnswerverifiedShow Answer

An example of a reaction controlled by enzyme multiplicity is

Correct AnswerverifiedShow Answer

Which of the following is a vasodilator that is derived from histidine?

Correct AnswerverifiedShow Answer

What is catalytic substrate channeling?

Correct AnswerverifiedChanneling increases the catalytic rate,...View AnswerShow Answer

Amino acid synthesis is primarily regulated by

Correct AnswerverifiedShow Answer

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C

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Acting as a human guinea pig,S...
View Answer

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A

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E

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Glyphosate (Roundup is one brand)acts by...
View Answer

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The methyl group on the side-chain of me...
View Answer

Correct Answer
verified

Correct Answer
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S-Adenosylmethionine is a prec...
View Answer

Correct Answer
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Correct Answer
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This unusual redox center is the site of...
View Answer

What process converts N₂ to NH₃?

Correct Answer
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Electrons are provided by ferredoxin,tra...
View Answer

Correct Answer
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Correct Answer
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Correct Answer
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Channeling increases the catalytic rate,...
View Answer

Correct Answer
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