Question 1

All of the following are true of transamination except:

Accepted Answer

A)   It is characterized by the transfer of an α-amino group from an amino acid to the α-keto position of an α-keto acid.
B)   The amino donor becomes an α-keto acid.
C)   The coenzyme needed is thiamine diphosphate.
D)   The α-keto acid acceptor becomes an α-amino acid.E) B) and D)
F) B) and C)

Question 2

The term ketogenic amino acids refers to amino acids

Accepted Answer

A)   that are precursors for glucose synthesis.
B)   that are degraded to yield acetyl CoA or acetoacetate
C)   that can not be converted to fatty acids or ketone bodies.
D)   that are degraded to yield succinyl-CoA, pyruvate, α-ketoglutarate, fumarate and oxaloacetate.
E)   None of these.F) B) and C)
G) A) and E)

Question 3

All of the following are metabolic intermediates of α-amino acid carbon skeletons except:

Accepted Answer

A)   pyridoxine
B)   α-ketoglutarate
C)   oxaloacetate
D)   succinyl-CoA
E)   fumarateF) A) and B)
G) A) and C)

Question 4

The two nitrogens in urea arise directly from:

Accepted Answer

A)   Ammonia and aspartic acid
B)   Carbamoyl phosphate and glutamic acid
C)   Ammonia and glutamic acid
D)   Carbamoyl phosphate and glutamineE) A) and C)
F) A) and B)

Question 5

Transamination of pyruvate with glutamate as the nitrogen donor gives:

Accepted Answer

A)   alanine
B)   serine
C)   cysteine
D)   aspartate
E)   tyrosineF) A) and E)
G) A) and D)

Question 6

The carbon chains of amino acids enter the major metabolic pathways through all of these compounds, except:

Accepted Answer

A)   α-ketoglutarate
B)   Pyruvate
C)   Glyceraldehyde
D)   Acetyl CoA
E)   All of these are entry points for amino acid catabolism.F) A) and B)
G) All of the above

Question 7

Write a mechanism for the formation of α-iminoglutarate from glutamate employing NAD+ as the oxidizing coenzyme.

Accepted Answer

Question 8

The appropriate sequence in the biosynthesis of proline from glutamate is: 1.NADPH reduction and release of Pi
2) Dehydration to 1-pyrroline-5-carboxylate
3) NADPH reduction of Schiff base
4) Phosphorylation to glutamate-5-phosphate

Accepted Answer

A)   4, 2, 1, 3
B)   4, 1, 2, 3
C)   1, 4, 3, 2
D)   1, 4, 2, 3
E)   2, 3, 1, 4F) B) and C)
G) D) and E)

Question 9

The carbon skeletons of specific amino acids cannot be used to replenish which of the following species associated with the citric acid cycle?

Accepted Answer

A)   pyruvate
B)   citrate
C)   fumarate
D)   succinyl CoA
E)   all of these can be usedF) C) and E)
G) A) and C)

Question 10

By a simple transamination reaction, intermediates in the Citric Acid Cycle can be converted in one step to all of these amino acids, except:

Accepted Answer

A)   Alanine
B)   Aspartic acid
C)   Glutamic acid
D)   Cysteine
E)   All of these amino acids are only one step away from the major metabolic pathways.F) B) and D)
G) B) and E)

Question 11

A coenzyme frequently encountered in transamination reactions is

Accepted Answer

A)   tetrahydrofolate
B)   pyridoxal phosphate
C)   thiamine pyrophosphate
D)   biotinE) A) and D)
F) A) and C)

Question 12

Many biological reactions are endergonic. Explain how it is possible that these reactions occur spontaneously.

Accepted Answer

Endergonic reactions such as the convers...

Exam 20: Amino Acid Metabolism

By a simple transamination reaction, intermediates in the Citric Acid Cycle can be converted in one step to all of these amino acids, except:

Correct Answer
verified

Transamination of pyruvate with glutamate as the nitrogen donor gives:

Correct Answer
verified

The term ketogenic amino acids refers to amino acids

Correct Answer
verified

The carbon chains of amino acids enter the major metabolic pathways through all of these compounds, except:

Correct Answer
verified

Many biological reactions are endergonic. Explain how it is possible that these reactions occur spontaneously.

Correct Answer
verified
Endergonic reactions such as the convers...
View Answer

The appropriate sequence in the biosynthesis of proline from glutamate is: 1.NADPH reduction and release of P_i 2) Dehydration to 1-pyrroline-5-carboxylate 3) NADPH reduction of Schiff base 4) Phosphorylation to glutamate-5-phosphate

Correct Answer
verified

All of the following are true of transamination except:

Correct Answer
verified

The two nitrogens in urea arise directly from:

Correct Answer
verified

A coenzyme frequently encountered in transamination reactions is

Correct Answer
verified

The carbon skeletons of specific amino acids cannot be used to replenish which of the following species associated with the citric acid cycle?

Correct Answer
verified

All of the following are metabolic intermediates of α-amino acid carbon skeletons except:

Correct Answer
verified

Write a mechanism for the formation of α-iminoglutarate from glutamate employing NAD⁺ as the oxidizing coenzyme.

Correct Answer
verified

Exam 20: Amino Acid Metabolism

By a simple transamination reaction, intermediates in the Citric Acid Cycle can be converted in one step to all of these amino acids, except:

Correct AnswerverifiedShow Answer

Transamination of pyruvate with glutamate as the nitrogen donor gives:

Correct AnswerverifiedShow Answer

The term ketogenic amino acids refers to amino acids

Correct AnswerverifiedShow Answer

The carbon chains of amino acids enter the major metabolic pathways through all of these compounds, except:

Correct AnswerverifiedShow Answer

Many biological reactions are endergonic. Explain how it is possible that these reactions occur spontaneously.

Correct AnswerverifiedEndergonic reactions such as the convers...View AnswerShow Answer

The appropriate sequence in the biosynthesis of proline from glutamate is: 1.NADPH reduction and release of Pi 2) Dehydration to 1-pyrroline-5-carboxylate 3) NADPH reduction of Schiff base 4) Phosphorylation to glutamate-5-phosphate

Correct AnswerverifiedShow Answer

All of the following are true of transamination except:

Correct AnswerverifiedShow Answer

The two nitrogens in urea arise directly from:

Correct AnswerverifiedShow Answer

A coenzyme frequently encountered in transamination reactions is

Correct AnswerverifiedShow Answer

The carbon skeletons of specific amino acids cannot be used to replenish which of the following species associated with the citric acid cycle?

Correct AnswerverifiedShow Answer

All of the following are metabolic intermediates of α-amino acid carbon skeletons except:

Correct AnswerverifiedShow Answer

Write a mechanism for the formation of α-iminoglutarate from glutamate employing NAD+ as the oxidizing coenzyme.

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Endergonic reactions such as the convers...
View Answer

The appropriate sequence in the biosynthesis of proline from glutamate is: 1.NADPH reduction and release of P_i 2) Dehydration to 1-pyrroline-5-carboxylate 3) NADPH reduction of Schiff base 4) Phosphorylation to glutamate-5-phosphate

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Write a mechanism for the formation of α-iminoglutarate from glutamate employing NAD⁺ as the oxidizing coenzyme.

Correct Answer
verified