Question 1

What is the difference between nitrogen fixation and nitrogen assimilation?

Accepted Answer

Nitrogen fixation is carried out by bact...

Question 2

The shikimate pathway can be defined as the pathway that involves the

Accepted Answer

A)   condensation of phosphoenolpyruvate and erythrose-4-phosphate.
B)   synthesis of essential amino acids from pyruvate.
C)   synthesis of essential amino acids from oxaloacetate.
D)   condensation of oxaloacetate and shikimate.E) A) and B)
F) All of the above

Question 3

How does biological fixation convert nitrogen to ammonia?

Accepted Answer

A)   by reducing nitrogen
B)   by combining nitrogen with carbon
C)   through the ATP-dependent process catalyzed by nitrogenase complex
D)   through the NADH-dependent process catalyzed by glutamate dehydrogenaseE) A) and C)
F) A) and B)

Question 4

Which of the following is the reaction for nitric oxide synthase?

Accepted Answer

A)   citrulline + NO + 1.5 NADP+  →\rightarrow→ L-arginine + 1.5 NADPH + H+ + 2O2
B)   L-arginine + 1.5 NADPH + H+ + 2O2 →\rightarrow→  citrulline + NO + 1.5 NADP+
C)   L-arginine + 1.5 NADPH + H+ + 2O2 →\rightarrow→  dopamine + NO + 1.5 NADP+
D)   L-arginine + 1.5 NADP+ + H+ + 2O2 →\rightarrow→  citrulline + NO + 1.5 NADPH E) A) and B)
F) A) and C)

Question 5

Aminotransferase reactions operate at  Δ\DeltaΔ G  °\degree° '   ≈\approx≈  0. What occurs when there is high substrate availability?

Accepted Answer

A)   Mostly reactants are made.
B)   Mostly products are made.
C)   Equal amount of products and reactants are made.
D)   This reaction is thermodynamically unfavorable. E) B) and C)
F) A) and D)

Question 6

Alkaptonuria is a disease coming from a deficiency in which pathway?

Accepted Answer

A)   group 1
B)   group 2
C)   group 3
D)   ureaE) All of the above
F) A) and B)

Question 7

How can the body easily adjust the relative levels of some amino acids using aminotransferases?

Accepted Answer

A)   Add ATP to the cell to produce more amino acids.
B)   Use common intermediates to interconvert between amino acids.
C)   Phosphorylate the amino acids to prevent them from being used.
D)   Remove NADH from the cell to produce more amino acids.E) B) and D)
F) C) and D)

Question 8

Group 2 pathways can be correctly described as pathways that

Accepted Answer

A)   degrade glucogenic amino acids to generate  α\alphaα -ketoglutarate.
B)   convert phenylalanine to tyrosine.
C)   degrade alanine.
D)   convert fumerate to oxaloacetate. E) All of the above
F) B) and D)

Question 9

Nitrite is oxidized by Nitrobacter bacteria to

Accepted Answer

A)   NO2.
B)   NO2  -  .
C)   NO -  .
D)   NO3  -  .E) C) and D)
F) B) and C)

Question 10

A person who has phenylketonuria must avoid which food additive?

Accepted Answer

A)   protein
B)   methanol
C)   aspartame
D)   phenylalanineE) A) and B)
F) All of the above

Question 11

What molecule signals the endothelial cell to produce NO?

Accepted Answer

A)   dopamine
B)   phosphate
C)   acetylcholine
D)   citrullineE) None of the above
F) A) and B)

Question 12

Using the figure below, summarize the synthesis of amino acids from oxaloacetate and pyruvate in E. coli.

Accepted Answer

Nine amino acids are synthesized from ox...

Question 13

After food enters the stomach, gastrin triggers the release of and secretion of .

Accepted Answer

A)   gastric juices; pepsinogen
B)   gastric juices; chyme
C)   chime; enteropeptidase
D)   secreton; enteropeptidaseE) A) and B)
F) A) and C)

Question 14

Both Nitrosomonas and Nitrobacter have a key role in nitrification. Nitrosomonas produces __________, whereas Nitrobacter produces .

Accepted Answer

A)   ammonia; nitrite
B)   nitrite; nitrate
C)   nitrate; nitrite
D)   nitrite; ammoniaE) A) and D)
F) B) and C)

Question 15

How are Roundup Ready soybeans resistant to the herbicide?

Accepted Answer

Glyphosate-resistant crops were develope...

Question 16

Nitrogen balance is best described as when the daily intake of equals the amount of __________ lost by excretion.

Accepted Answer

A)   ammonia; nitrogen
B)   nitrogen; nitrogen
C)   glucose; glucose
D)   nitrogen; ammoniaE) A) and D)
F) A) and C)

Question 17

Agricultural fertilizers provide the ground with nitrate and nitrite, but only ammonia can be assimilated by plants. What process converts nitrate and nitrite to ammonia?

Accepted Answer

A)   nitrification
B)   ammonia assimilation
C)   nitrogen fixation
D)   nitrogen assimilationE) A) and B)
F) A) and C)

Question 18

A no-protein diet with high doses of L-arginine helps patients with argininosuccinase deficiency because it __________ the concentration of _.

Accepted Answer

A)   increases; fumerate that is metabolized by the citric acid cycle to lower ammonia levels
B)   increases; ammonia in the diet to keep them regulated
C)   increases; ornithine that is needed to maintain flux through the urea cycle
D)   decreases; citrulline to prevent ammonia toxicityE) A) and B)
F) A) and D)

Question 19

Which of the following is the net reaction of the urea cycle?

Accepted Answer

A)   Urea + Fumerate + 2 ADP + 2Pi + AMP + PPi  →\rightarrow→  NH+ + HCO3- + aspartate + 3ATP
B)   NH+ + HCO3  -  + aspartate + 3ATP  →\rightarrow→  urea + fumerate + 2 ADP + 2Pi + AMP + PPi
C)   NH+ + HCO3  -  + fumerate + 3ATP  →\rightarrow→  urea + aspartate + 2 ADP + 2Pi + AMP + PPi
D)   NH+ + HCO3  -  + aspartate + 2 ADP + 2Pi + AMP + PPi  →\rightarrow→  urea + fumerate + 3ATP E) None of the above
F) C) and D)

Question 20

The urea cycle's function is to the body of an organism.

Accepted Answer

A)   remove excess sugar from
B)   remove excess water-soluble vitamins from
C)   remove excess nitrogen from
D)   add additional nitrogen toE) A) and B)
F) None of the above

Exam 17: Amino Acid Metabolism

Which of the following is the reaction for nitric oxide synthase?

Correct AnswerverifiedShow Answer

How can the body easily adjust the relative levels of some amino acids using aminotransferases?

Correct AnswerverifiedShow Answer

Using the figure below, summarize the synthesis of amino acids from oxaloacetate and pyruvate in E. coli.

Correct AnswerverifiedNine amino acids are synthesized from ox...View AnswerShow Answer

The shikimate pathway can be defined as the pathway that involves the

Correct AnswerverifiedShow Answer

A no-protein diet with high doses of L-arginine helps patients with argininosuccinase deficiency because it __________ the concentration of _.

Correct AnswerverifiedShow Answer

Which of the following is the net reaction of the urea cycle?

Correct AnswerverifiedShow Answer

Alkaptonuria is a disease coming from a deficiency in which pathway?

Correct AnswerverifiedShow Answer

How does biological fixation convert nitrogen to ammonia?

Correct AnswerverifiedShow Answer

A person who has phenylketonuria must avoid which food additive?

Correct AnswerverifiedShow Answer

Nitrogen balance is best described as when the daily intake of equals the amount of __________ lost by excretion.

Correct AnswerverifiedShow Answer

Group 2 pathways can be correctly described as pathways that

Correct AnswerverifiedShow Answer

What is the difference between nitrogen fixation and nitrogen assimilation?

Correct AnswerverifiedNitrogen fixation is carried out by bact...View AnswerShow Answer

Nitrite is oxidized by Nitrobacter bacteria to

Correct AnswerverifiedShow Answer

How are Roundup Ready soybeans resistant to the herbicide?

Correct AnswerverifiedGlyphosate-resistant crops were develope...View AnswerShow Answer

After food enters the stomach, gastrin triggers the release of and secretion of .

Correct AnswerverifiedShow Answer

The urea cycle's function is to the body of an organism.

Correct AnswerverifiedShow Answer

Both Nitrosomonas and Nitrobacter have a key role in nitrification. Nitrosomonas produces __________, whereas Nitrobacter produces .

Correct AnswerverifiedShow Answer

What molecule signals the endothelial cell to produce NO?

Correct AnswerverifiedShow Answer

Aminotransferase reactions operate at Δ\DeltaΔ G °\degree° ' ≈\approx≈ 0. What occurs when there is high substrate availability?

Correct AnswerverifiedShow Answer

Agricultural fertilizers provide the ground with nitrate and nitrite, but only ammonia can be assimilated by plants. What process converts nitrate and nitrite to ammonia?

Correct AnswerverifiedShow Answer

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Nine amino acids are synthesized from ox...
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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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Nitrogen fixation is carried out by bact...
View Answer

Correct Answer
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Correct Answer
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Glyphosate-resistant crops were develope...
View 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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Aminotransferase reactions operate at $\Delta$ G $\degree$ ^' $\approx$ 0. What occurs when there is high substrate availability?

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Correct Answer
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