Question 1

Which of the following is an allosteric activator of mammalian carbamoyl phosphate synthetase?

Accepted Answer

A)   α-ketoglutarate
B)   N-acetylaspartate
C)   N-acetylglutamate
D)   glutamine
E)   None of the above. C

Question 2

Which amino acids can be converted to pyruvate by a single enzyme-catalyzed reaction?

Accepted Answer

Alanine can be converted to py...

Question 3

What is the basic strategy by which proteins are degraded?

Accepted Answer

Proteins are degraded to amino acids and...

Question 4

Choose the correct answer from the list below. Not all of the answers will be used.
-The product _______________ results when aspartate is transaminated with ɑ-ketoglutarate.

Accepted Answer

A)  hyperammonemia
B)  aminotransferases
C)  methionine
D)  S-adenosylmethionine
E)  glutamate dehydrogenaseF) oxaloacetateG) biopterinH) glutamateI) hippurateJ) ureaK) dehydrataseL) dioxygenasesM) ammonia disorder

Question 5

What is the cause of PKU? Give the structure of the abnormal metabolite that accumulates from which this condition gets its name.

Accepted Answer

PKU is the abbreviation for phenylketonu...

Question 6

Uricotelic organisms release nitrogen as:

Accepted Answer

A)   NH4+.
B)   arginine.
C)   uric acid.
D)   All of the above.
E)   None of the above. C

Question 7

Choose the correct answer from the list below. Not all of the answers will be used.
-Serine and threonine are deaminated by the enzyme _______________.

Accepted Answer

A)  hyperammonemia
B)  aminotransferases
C)  methionine
D)  S-adenosylmethionine
E)  glutamate dehydrogenaseF) oxaloacetateG) biopterinH) glutamateI) hippurateJ) ureaK) dehydrataseL) dioxygenasesM) ammonia disorder

Question 8

The genetic deficiency of the enzyme ___________________ results in a condition referred to as phenylketonuria.

Accepted Answer

phenylalan...

Question 9

In addition to increased fatty acid accumulation in the liver, excess consumption of ethanol can also induce two further stages of liver damage. What are they?

Accepted Answer

The second stage is alcoholic ...

Question 10

Why do you think that weight lifters take large amounts of branched-chain amino acids?

Accepted Answer

Branch chain amino acids are c...

Question 11

The hydrolysis of arginine by arginase produces ornithine and ___________________.

Accepted Answer

The answer of The hydrolysis of arginine by arginase produces...

Question 12

Which amino acids supply carbons for eventual entry into metabolism as succinyl CoA?

Accepted Answer

A)   Methionine, Valine, Leucine
B)   Methionine, Isoleucine, Valine
C)   Isoleucine, Valine, Leucine
D)   All of the above.
E)   None of the above.

Question 13

In the first step of the urea cycle, CO2 and NH4+ are converted into ___________________.

Accepted Answer

Question 14

Write the net equation of the urea cycle and indicate whether energy is produced or consumed by the cycle.

Accepted Answer

CO2 + NH4+ + 3 ATP + Asp + 2 H...

Question 15

What type of damage occurs if there is a defect in the urea cycle?

Accepted Answer

A defect in this cycle causes hyperammonemia (large amount of NH4+). Genetic defects become obvious immediately. After lethargy and vomiting begins, coma and brain damage follow, most likely caused by the high levels of glutamate and glutamine in the brain.

Question 16

In the urea cycle, the second nitrogen of urea enters the cycle in the form of which of the following metabolites?

Accepted Answer

A)   alanine
B)   glutamine
C)   ornithine
D)   aspartate
E)   arginine

Question 17

In the degradation of amino acids, the amino nitrogens can eventually become the amino group of ___________________.

Accepted Answer

The answer of In the degradation of amino acids, the...

Question 18

Choose the correct answer from the list below. Not all of the answers will be used.
-The ______________ enzymes transfer an ɑ-amino group from amino acids to ɑ-ketoglutarate.

Accepted Answer

A)  hyperammonemia
B)  aminotransferases
C)  methionine
D)  S-adenosylmethionine
E)  glutamate dehydrogenaseF) oxaloacetateG) biopterinH) glutamateI) hippurateJ) ureaK) dehydrataseL) dioxygenasesM) ammonia disorder

Question 19

Which amino acids can be directly deaminated to produce NH4+?

Accepted Answer

A)   serine and threonine
B)   serine, asparagine, and threonine
C)   proline and threonine
D)   serine and valine
E)   None of the above.

Question 20

Choose the correct answer from the list below. Not all of the answers will be used.
-The methyl group donor _______________ is the product of the first step of methionine degradation.

Accepted Answer

A)  hyperammonemia
B)  aminotransferases
C)  methionine
D)  S-adenosylmethionine
E)  glutamate dehydrogenaseF) oxaloacetateG) biopterinH) glutamateI) hippurateJ) ureaK) dehydrataseL) dioxygenasesM) ammonia disorder

Exam 30: Amino Acid Degradation and the Urea Cycle

Which of the following is an allosteric activator of mammalian carbamoyl phosphate synthetase?

Correct AnswerverifiedC

Which amino acids can be converted to pyruvate by a single enzyme-catalyzed reaction?

Correct AnswerverifiedAlanine can be converted to py...View AnswerShow Answer

What is the basic strategy by which proteins are degraded?

Correct AnswerverifiedProteins are degraded to amino acids and...View AnswerShow Answer

Choose the correct answer from the list below. Not all of the answers will be used. -The product _______________ results when aspartate is transaminated with ɑ-ketoglutarate.

Correct AnswerverifiedShow Answer

What is the cause of PKU? Give the structure of the abnormal metabolite that accumulates from which this condition gets its name.

Correct AnswerverifiedPKU is the abbreviation for phenylketonu...View AnswerShow Answer

Uricotelic organisms release nitrogen as:

Correct AnswerverifiedC

Choose the correct answer from the list below. Not all of the answers will be used. -Serine and threonine are deaminated by the enzyme _______________.

Correct AnswerverifiedShow Answer

The genetic deficiency of the enzyme ___________________ results in a condition referred to as phenylketonuria.

Correct Answerverifiedphenylalan...View AnswerShow Answer

In addition to increased fatty acid accumulation in the liver, excess consumption of ethanol can also induce two further stages of liver damage. What are they?

Correct AnswerverifiedThe second stage is alcoholic ...View AnswerShow Answer

Why do you think that weight lifters take large amounts of branched-chain amino acids?

Correct AnswerverifiedBranch chain amino acids are c...View AnswerShow Answer

The hydrolysis of arginine by arginase produces ornithine and ___________________.

Correct AnswerverifiedShow Answer

Which amino acids supply carbons for eventual entry into metabolism as succinyl CoA?

Correct AnswerverifiedShow Answer

In the first step of the urea cycle, CO2 and NH4+ are converted into ___________________.

Correct AnswerverifiedShow Answer

Write the net equation of the urea cycle and indicate whether energy is produced or consumed by the cycle.

Correct AnswerverifiedCO2 + NH4+ + 3 ATP + Asp + 2 H...View AnswerShow Answer

What type of damage occurs if there is a defect in the urea cycle?

Correct AnswerverifiedA defect in this cycle causes hyperammonemia (large amount of NH4+). Genetic defects become obvious immediately. After lethargy and vomiting begins, coma and brain damage follow, most likely caused by the high levels of glutamate and glutamine in the brain.

In the urea cycle, the second nitrogen of urea enters the cycle in the form of which of the following metabolites?

Correct AnswerverifiedShow Answer

In the degradation of amino acids, the amino nitrogens can eventually become the amino group of ___________________.

Correct AnswerverifiedShow Answer

Choose the correct answer from the list below. Not all of the answers will be used. -The ______________ enzymes transfer an ɑ-amino group from amino acids to ɑ-ketoglutarate.

Correct AnswerverifiedShow Answer

Which amino acids can be directly deaminated to produce NH4+?

Correct AnswerverifiedShow Answer

Choose the correct answer from the list below. Not all of the answers will be used. -The methyl group donor _______________ is the product of the first step of methionine degradation.

Correct AnswerverifiedShow Answer

Correct Answer
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C

Correct Answer
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Alanine can be converted to py...
View Answer

Correct Answer
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Proteins are degraded to amino acids and...
View Answer

Correct Answer
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Correct Answer
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PKU is the abbreviation for phenylketonu...
View Answer

Correct Answer
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C

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phenylalan...
View Answer

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The second stage is alcoholic ...
View Answer

Correct Answer
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Branch chain amino acids are c...
View Answer

Correct Answer
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In the first step of the urea cycle, CO₂ and NH⁴⁺ are converted into ___________________.

Correct Answer
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Correct Answer
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CO2 + NH4+ + 3 ATP + Asp + 2 H...
View Answer

Correct Answer
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A defect in this cycle causes hyperammonemia (large amount of NH4+). Genetic defects become obvious immediately. After lethargy and vomiting begins, coma and brain damage follow, most likely caused by the high levels of glutamate and glutamine in the brain.

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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