Question 1

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

Question 2

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 
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 3

The structure shown below is .

Accepted Answer

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

Question 4

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

Question 5

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

Question 6

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

Question 7

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 8

In the urea cycle the nitrogen atoms originate from .

Accepted Answer

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

Question 9

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

Accepted Answer

A) True 
 B)False

Question 10

Nitrogenase catalyzes the reduction of N2 to nitrate.

Accepted Answer

A) True 
 B)False

Question 11

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

Question 12

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

Question 13

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

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

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

The structure shown below is .

Nitric oxide is produced from which reaction?

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

Which amino acids are purely ketogenic?

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.

In the urea cycle the nitrogen atoms originate from .

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

Nitrogenase catalyzes the reduction of N₂to nitrate.

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

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

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

Introduction to Biochemistry

Water

Amino Acids and the Primary Structures of Proteins

Proteins: Three-Dimensional Structure and Function

Properties of Enzymes

Mechanisms of Enzymes

Coenzymes and Vitamins

Carbohydrates

Lipids and Membranes

Introduction to Metabolism

Glycolysis

Gluconeogenesis, the Pentose Phosphate Pathway, and Glycogen Metabolism

The Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Lipid Metabolism

Nucleotide Metabolism

Nucleic Acids

Dna Replication, Repair, and Recombination

Transcription and Rna Processing

Protein Synthesis

Recombinant Dna Technology

Filters

Exam 17: Amino Acid Metabolism

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

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

The structure shown below is .

Nitric oxide is produced from which reaction?

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

Which amino acids are purely ketogenic?

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.

In the urea cycle the nitrogen atoms originate from .

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

Nitrogenase catalyzes the reduction of N2 to nitrate.

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

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

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

Introduction to Biochemistry

Water

Amino Acids and the Primary Structures of Proteins

Proteins: Three-Dimensional Structure and Function

Properties of Enzymes

Mechanisms of Enzymes

Coenzymes and Vitamins

Carbohydrates

Lipids and Membranes

Introduction to Metabolism

Glycolysis

Gluconeogenesis, the Pentose Phosphate Pathway, and Glycogen Metabolism

The Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Lipid Metabolism

Nucleotide Metabolism

Nucleic Acids

Dna Replication, Repair, and Recombination

Transcription and Rna Processing

Protein Synthesis

Recombinant Dna Technology

Filters

Nitrogenase catalyzes the reduction of N₂to nitrate.