Question 1

Tryptophan synthaseʹs a subunit catalyzes the cleavage of indole glycerol phosphate to glyceralde 3-phosphate and indole.

Accepted Answer

A) True 
 B)False

Question 2

A key precursor in the synthesis of aromatic amino acids tryptophan, tyrosine and phenylalanine)  is .

Accepted Answer

A)   prephenate
B)   chorismate
C)   4-hydroxyphenylpyruvate
D)   indole

Question 3

Which amino acids are purely ketogenic?

Accepted Answer

A)   arginine and lysine
B)   valine and isoleucine
C)   tryptophan only
D)   lysine and leucine
E)   all essential amino acids

Question 4

Nitrogenase catalyzes the reduction of N2 to nitrate.

Accepted Answer

A) True 
 B)False

Question 5

Nitric oxide is produced from which reaction?

Accepted Answer

A)   arginine to citrulline
B)   glutamate to α-ketoglutarate
C)   bicarbonate to carbamoyl phosphate
D)   tryptophan to acetyl CoA

Question 6

The structure shown below is .

Accepted Answer

A)   urea
B)   uridine
C)   uric acid
D)   carbodiamine

Question 7

At neutral pH, the main ionic form of ammonia is .

Accepted Answer

A)   N2
B)   NH4+
C)   NH3
D)   NH2-
E)   None of the above

Question 8

Which of the following is/are true concerning transanimation reactions?

Accepted Answer

A)   They can convert a-keto acids to a-amino acids.
B)   All require the coenzyme pyridoxal phosphate.
C)   The catalyzed reactions are near-equilibrium.
D)   All of the above

Question 9

In the urea cycle the nitrogen atoms originate from .

Accepted Answer

A)   α-ketoglutarate
B)   ornithine
C)   lysine
D)   aspartate

Question 10

Defects in which of the following may result in elevated levels of phenylalanine?

Accepted Answer

A)   deficiencies in dihydropteridine reductase
B)   deficiencies in 4a-carbinolamine dehydratase
C)   defects in the biosynthesis of tetrahydrobiopterin
D)   All of the above

Question 11

Microorganisms capable of fixing nitrogen into a form usable by animals obtain the energy for this process from .

Accepted Answer

A)   lightning
B)   oxidation and reduction respiration) 
C)   photosynthesis of host plants
D)   soil nutrients

Question 12

Periportal cells of the liver are nearest to the inflow of blood and have a higher capacity for urea synthesis than the perivenous cells that are near the outflow.

Accepted Answer

A) True 
 B)False

Question 13

What would be the product of the transamination of the structure shown below? The unionized forms are shown.)

Accepted Answer

A)   I
B)   II
C)   III
D)   IV

Exam 17: Amino Acid Metabolism

A key precursor in the synthesis of aromatic amino acids tryptophan, tyrosine and phenylalanine) is .

Correct Answer
verified

Tryptophan synthaseʹs a subunit catalyzes the cleavage of indole glycerol phosphate to glyceralde 3-phosphate and indole.

Correct Answer
verified

What would be the product of the transamination of the structure shown below? The unionized forms are shown.)

Correct Answer
verified

Defects in which of the following may result in elevated levels of phenylalanine?

Correct Answer
verified

At neutral pH, the main ionic form of ammonia is .

Correct Answer
verified

Which of the following is/are true concerning transanimation reactions?

Correct Answer
verified

In the urea cycle the nitrogen atoms originate from .

Correct Answer
verified

Microorganisms capable of fixing nitrogen into a form usable by animals obtain the energy for this process from .

Correct Answer
verified

Which amino acids are purely ketogenic?

Correct Answer
verified

Periportal cells of the liver are nearest to the inflow of blood and have a higher capacity for urea synthesis than the perivenous cells that are near the outflow.

Correct Answer
verified

Nitrogenase catalyzes the reduction of N₂to nitrate.

Correct Answer
verified

The structure shown below is .

Correct Answer
verified

Nitric oxide is produced from which reaction?

Correct Answer
verified

Exam 17: Amino Acid Metabolism

A key precursor in the synthesis of aromatic amino acids tryptophan, tyrosine and phenylalanine) is .

Correct AnswerverifiedShow Answer

Tryptophan synthaseʹs a subunit catalyzes the cleavage of indole glycerol phosphate to glyceralde 3-phosphate and indole.

Correct AnswerverifiedShow Answer

What would be the product of the transamination of the structure shown below? The unionized forms are shown.)

Correct AnswerverifiedShow Answer

Defects in which of the following may result in elevated levels of phenylalanine?

Correct AnswerverifiedShow Answer

At neutral pH, the main ionic form of ammonia is .

Correct AnswerverifiedShow Answer

Which of the following is/are true concerning transanimation reactions?

Correct AnswerverifiedShow Answer

In the urea cycle the nitrogen atoms originate from .

Correct AnswerverifiedShow Answer

Microorganisms capable of fixing nitrogen into a form usable by animals obtain the energy for this process from .

Correct AnswerverifiedShow Answer

Which amino acids are purely ketogenic?

Correct AnswerverifiedShow Answer

Periportal cells of the liver are nearest to the inflow of blood and have a higher capacity for urea synthesis than the perivenous cells that are near the outflow.

Correct AnswerverifiedShow Answer

Nitrogenase catalyzes the reduction of N2 to nitrate.

Correct AnswerverifiedShow Answer

The structure shown below is .

Correct AnswerverifiedShow Answer

Nitric oxide is produced from which reaction?

Correct AnswerverifiedShow Answer

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
verified

Nitrogenase catalyzes the reduction of N₂to nitrate.

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified