Question 1

Nitrate can be reduced to ammonia by virtually all organisms.

Accepted Answer

A) True 
 B)False

Question 2

The common degradation product of lysine, tryptophan, phenylalanine and tyrosine is ________.

Accepted Answer

The answer of The common degradation product of lysine, tryptophan,...

Question 3

All amino acids can be synthesized from intermediates of the:

Accepted Answer

A)   glycolytic pathway alone.
B)   glycolytic pathway and the pentose phosphate pathway.
C)   citric acid cycle alone.
D)   the glycolytic pathway and citric acid cycle.
E)   the glycolytic pathway, the pentose phosphate pathway and citric acid cycle.F) A) and B)
G) A) and E) E

Question 4

Tyrosine is the precursor of serotonin which has a number of roles in the nervous system.

Accepted Answer

A) True 
 B)False

Question 5

The catecholamine neurotransmitters are derived from ________.

Accepted Answer

The answer of The catecholamine neurotransmitters are derived from ________....

Question 6

Transamination reactions can be used to degrade or synthesize amino acids because they have an ________ that has a value close to one.

Accepted Answer

equilibrium constant

Question 7

________ high energy phosphates from ATP are consumed in each turn of the urea cycle.

Accepted Answer

The answer of ________ high energy phosphates from ATP are...

Question 8

Apart from in the synthesis of methionine, S-adenosylmethionine is the only biological ________ group donor.

Accepted Answer

The answer of Apart from in the synthesis of methionine,...

Question 9

N2 gas can be converted to NH3 by:

Accepted Answer

A)   most organisms.
B)   mammals.
C)   all plants.
D)   all bacteria.
E)   legumes.F) A) and E)
G) A) and B)

Question 10

The oxidation of branched chain amino acids shares a similar chemical strategy with β-oxidation of fatty acids.

Accepted Answer

A) True 
 B)False

Question 11

Tetrahydrofolate is a coenzyme involved in the mobilization and utilization of single carbon functional units in the:

Accepted Answer

A)   metabolism of serine, glycine, methionine, and histidine.
B)   biosynthesis of purine nucleotides.
C)   biosynthesis of thymine.
D)   biosynthesis of formylmethionyl-tRNA.
E)   all of the above.F) C) and D)
G) A) and E)

Question 12

Pyridoxal phosphate is a versatile coenzyme as it is capable of forming a stable ________ base between an amino acid substrate and the coenzyme.

Accepted Answer

The answer of Pyridoxal phosphate is a versatile coenzyme as...

Question 13

Folate deficiency results in increased risk of cardiovascular disease associated with abnormally high levels of serum ________ due to decreased levels of tetrahydrofolate cofactors required for the methionine synthase reaction.

Accepted Answer

The answer of Folate deficiency results in increased risk of...

Question 14

Which of the following enzymes is NOT involved in the conversion of NH3 to an organic nitrogen-containing compound?

Accepted Answer

A)   Glutamate dehydrogenase
B)   Carbamoyl phosphate dehydrogenase
C)   Glutamate-oxaloacetate transaminase
D)   Glutamine synthetase
E)   Asparagine synthetaseF) B) and C)
G) B) and D)

Question 15

Nitrogen fixation requires the hydrolysis of 8 ATPs to produce 2 NH3 molecules from 1 N2.

Accepted Answer

A) True 
 B)False

Question 16

Which of the following amino acids is both glucogenic and ketogenic?

Accepted Answer

A)   Lysine
B)   Leucine
C)   Tryptophan
D)   Cysteine
E)   ArginineF) None of the above
G) A) and E) C

Question 17

Which of the following amino acids cannot be used to provide an intermediate of the citric acid cycle?

Accepted Answer

A)   Histidine
B)   Proline
C)   Phenylalanine
D)   Lysine
E)   TyrosineF) B) and C)
G) A) and D)

Question 18

The H2S produced by metabolism of cysteine is a waste product with no physiological or biochemical function.

Accepted Answer

A) True 
 B)False

Question 19

In the degradation of amino acids in muscle NH4+ is carried to the liver for conversion into urea by:

Accepted Answer

A)   glutamine.
B)   asparagine.
C)   alanine.
D)   either alanine or glutamine.
E)   any amino acid.F) A) and B)
G) All of the above

Question 20

The Krebs-Henseleit urea cycle takes place in liver cells entirely within the mitochondrion.

Accepted Answer

A) True 
 B)False

Exam 18: Amino Acid and Nitrogen Metabolism

Nitrate can be reduced to ammonia by virtually all organisms.

Correct AnswerverifiedShow Answer

The common degradation product of lysine, tryptophan, phenylalanine and tyrosine is ________.

Correct AnswerverifiedShow Answer

All amino acids can be synthesized from intermediates of the:

Correct AnswerverifiedE

Tyrosine is the precursor of serotonin which has a number of roles in the nervous system.

Correct AnswerverifiedShow Answer

The catecholamine neurotransmitters are derived from ________.

Correct AnswerverifiedShow Answer

Transamination reactions can be used to degrade or synthesize amino acids because they have an ________ that has a value close to one.

Correct Answerverifiedequilibrium constant

________ high energy phosphates from ATP are consumed in each turn of the urea cycle.

Correct AnswerverifiedShow Answer

Apart from in the synthesis of methionine, S-adenosylmethionine is the only biological ________ group donor.

Correct AnswerverifiedShow Answer

N2 gas can be converted to NH3 by:

Correct AnswerverifiedShow Answer

The oxidation of branched chain amino acids shares a similar chemical strategy with β-oxidation of fatty acids.

Correct AnswerverifiedShow Answer

Tetrahydrofolate is a coenzyme involved in the mobilization and utilization of single carbon functional units in the:

Correct AnswerverifiedShow Answer

Pyridoxal phosphate is a versatile coenzyme as it is capable of forming a stable ________ base between an amino acid substrate and the coenzyme.

Correct AnswerverifiedShow Answer

Folate deficiency results in increased risk of cardiovascular disease associated with abnormally high levels of serum ________ due to decreased levels of tetrahydrofolate cofactors required for the methionine synthase reaction.

Correct AnswerverifiedShow Answer

Which of the following enzymes is NOT involved in the conversion of NH3 to an organic nitrogen-containing compound?

Correct AnswerverifiedShow Answer

Nitrogen fixation requires the hydrolysis of 8 ATPs to produce 2 NH3 molecules from 1 N2.

Correct AnswerverifiedShow Answer

Which of the following amino acids is both glucogenic and ketogenic?

Correct AnswerverifiedC

Which of the following amino acids cannot be used to provide an intermediate of the citric acid cycle?

Correct AnswerverifiedShow Answer

The H2S produced by metabolism of cysteine is a waste product with no physiological or biochemical function.

Correct AnswerverifiedShow Answer

In the degradation of amino acids in muscle NH4+ is carried to the liver for conversion into urea by:

Correct AnswerverifiedShow Answer

The Krebs-Henseleit urea cycle takes place in liver cells entirely within the mitochondrion.

Correct AnswerverifiedShow Answer

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E

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equilibrium constant

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C

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