Question 1

In the nitrogen cycle, one main method for ammonia entering is

Accepted Answer

A)  decomposition of organic material by invertebrates. 
B)  from the atmosphere. 
C)  through denitrification. 
D)  by leghemoglobin. 
A)  decomposition of organic material by invertebrates. 
B)  from the atmosphere. 
C)  through denitrification. 
D)  by leghemoglobin.

Question 2

In the duodenum, enteropeptidase

Accepted Answer

A)  cleaves trypsinogen to form trypsin. 
B)  cleaves chymotrypsinogen to form chymotrypsin. 
C)  generates peptides and amino acids. 
D)  neutralizes the pH of the duodenum to a pH of 7. 
A)  cleaves trypsinogen to form trypsin. 
B)  cleaves chymotrypsinogen to form chymotrypsin. 
C)  generates peptides and amino acids. 
D)  neutralizes the pH of the duodenum to a pH of 7.

Question 3

Which intermediate is shared by the urea cycle and the citric acid cycle?

Accepted Answer

A)  citrulline 
B)  argininosuccinate 
C)  aspartate 
D)  malate 
A)  citrulline 
B)  argininosuccinate 
C)  aspartate 
D)  malate

Question 4

Nitrogen in biological compounds ultimately comes from what source?

Accepted Answer

A)  ammonia 
B)  nitrate 
C)  nitrogen gas 
D)  bacteria 
A)  ammonia 
B)  nitrate 
C)  nitrogen gas 
D)  bacteria

Question 5

The recycling of fumerate helps offset the energy cost of the urea cycle because fumerate helps generate

Accepted Answer

A)  arginine to produce 2 ATP. 
B)  citrulline to produce NADPH, which can generate 3 ATP. 
C)  oxaloacetate to produce NADH, which can generate 2.5 ATP. 
D)  urea, which will make more ATP. 
A)  arginine to produce 2 ATP. 
B)  citrulline to produce NADPH, which can generate 3 ATP. 
C)  oxaloacetate to produce NADH, which can generate 2.5 ATP. 
D)  urea, which will make more ATP.

Question 6

If plants and bacteria were unable to produce glutamate from ammonia, a possible outcome would be that plants would

Accepted Answer

A)  be able to produce more nucleotides. 
B)  no longer be able to produce other amino acids. 
C)  not be able to complete glycolysis. 
D)  be able to produce more ATP. 
A)  be able to produce more nucleotides. 
B)  no longer be able to produce other amino acids. 
C)  not be able to complete glycolysis. 
D)  be able to produce more ATP.

Question 7

The Haber process is 98% efficient. How does it achieve that level of efficiency?

Accepted Answer

A)  low temperatures and atmospheric pressure 
B)  low pressures and recycling unreacted nitrogen 
C)  high pressures and recycling nitrogen 
D)  high pressures and high concentrations of nitrogen 
A)  low temperatures and atmospheric pressure 
B)  low pressures and recycling unreacted nitrogen 
C)  high pressures and recycling nitrogen 
D)  high pressures and high concentrations of nitrogen

Question 8

Aspartate is a(n) amino acid, so if a person had a diet that contained no aspartate, .

Accepted Answer

A)  essential; death would occur 
B)  nonessential; aspartate could be synthesized from other intermediates 
C)  essential; aspartate could be synthesized from other intermediates 
D)  nonessential; death would occur 
A)  essential; death would occur 
B)  nonessential; aspartate could be synthesized from other intermediates 
C)  essential; aspartate could be synthesized from other intermediates 
D)  nonessential; death would occur

Question 9

Which metabolic process is the cause of albinism?

Accepted Answer

A)  inefficient production of dopamine 
B)  the enzyme tyrosinase working inefficiently 
C)  overproduction of NADPH 
D)  low levels of ATP available in the cell 
A)  inefficient production of dopamine 
B)  the enzyme tyrosinase working inefficiently 
C)  overproduction of NADPH 
D)  low levels of ATP available in the cell

Question 10

Aminotransferase reaction is an example of what kind of kinetics?

Accepted Answer

A)  ternary 
B)  ping-pong 
C)  cooperative 
D)  reversible 
A)  ternary 
B)  ping-pong 
C)  cooperative 
D)  reversible

Question 11

Compare and contrast the known porphyrias.

Accepted Answer

See Figure 17.55 in the text.

Question 12

A person who has phenylketonuria will have a buildup of which molecule in the cell?

Accepted Answer

A)  tyrosine 
B)  phenylalanine 
C)  pyruvate 
D)  alanine 
A)  tyrosine 
B)  phenylalanine 
C)  pyruvate 
D)  alanine

Question 13

Distinguish between the first and second stages of the aminotransferase reaction.

Accepted Answer

In the first stage of the reaction the @#LAT-DLM&-

Question 14

What amino acid serves as the precursor to heme?

Accepted Answer

A)  histidine 
B)  asparagine 
C)  glycine 
D)  glutamine 
A)  histidine 
B)  asparagine 
C)  glycine 
D)  glutamine

Question 15

Bacteria in the genus Nitrosomonas are able to oxidize ammonia to what final product?

Accepted Answer

A)  NO2 
B)  NO3  - 
C)  NO4 - 
D)  NO2  - 
A)  NO2 
B)  NO3  - 
C)  NO4 - 
D)  NO2  -

Question 16

Which intermediates of the Krebs bicycle would be found in the cytosol?

Accepted Answer

A)  fumerate and argininosuccinate 
B)  citrulline and malate 
C)  arginine and oxaloacetate 
D)  urea and ammonia 
A)  fumerate and argininosuccinate 
B)  citrulline and malate 
C)  arginine and oxaloacetate 
D)  urea and ammonia

Question 17

Which three enzymes mediate ammonia assimilation?

Accepted Answer

A)  glutamine synthase, glutamate synthetase, glutamate hydrogenase 
B)  glutamine synthetase, glutamate synthase, glutamate dehydrogenase 
C)  glutamine oxidase, glutamate reductase, glutamate dehydrogenase 
D)  glutamine dehydrogenase, glutamate synthase, glutamate oxidase 
A)  glutamine synthase, glutamate synthetase, glutamate hydrogenase 
B)  glutamine synthetase, glutamate synthase, glutamate dehydrogenase 
C)  glutamine oxidase, glutamate reductase, glutamate dehydrogenase 
D)  glutamine dehydrogenase, glutamate synthase, glutamate oxidase

Question 18

Outline the process of protein degradation by the ubiquitin proteasome pathway.

Accepted Answer

The ubiquitin proteasome pathway takes t

Question 19

What purpose does nitrogen fixation and assimilation serve in the biosphere?

Accepted Answer

Nitrogen fixation takes place in bacteri

Question 20

Explain the mechanism by which glyphosate inhibits the production of aromatic amino acids in plants.

Accepted Answer

Glyphosate is a competitive inhibitor of

Exam 17: Amino Acid Metabolism

In the nitrogen cycle, one main method for ammonia entering is

In the duodenum, enteropeptidase

Which intermediate is shared by the urea cycle and the citric acid cycle?

Nitrogen in biological compounds ultimately comes from what source?

The recycling of fumerate helps offset the energy cost of the urea cycle because fumerate helps generate

If plants and bacteria were unable to produce glutamate from ammonia, a possible outcome would be that plants would

The Haber process is 98% efficient. How does it achieve that level of efficiency?

Aspartate is a(n) amino acid, so if a person had a diet that contained no aspartate, .

Which metabolic process is the cause of albinism?

Aminotransferase reaction is an example of what kind of kinetics?

Compare and contrast the known porphyrias.

A person who has phenylketonuria will have a buildup of which molecule in the cell?

Distinguish between the first and second stages of the aminotransferase reaction.

What amino acid serves as the precursor to heme?

Bacteria in the genus Nitrosomonas are able to oxidize ammonia to what final product?

Which intermediates of the Krebs bicycle would be found in the cytosol?

Which three enzymes mediate ammonia assimilation?

Outline the process of protein degradation by the ubiquitin proteasome pathway.

What purpose does nitrogen fixation and assimilation serve in the biosphere?

Explain the mechanism by which glyphosate inhibits the production of aromatic amino acids in plants.

Principles of Biochemistry

Physical Biochemistry: Energy Conversion, Water, and Membranes

Nucleic Acid Structure and Function

Protein Structure

Methods in Protein Biochemistry

Protein Function

Enzyme Mechanisms

Cell Signaling Systems

Glycolysis: a Paradigm of Metabolic Regulation

The Citrate Cycle

Oxidative Phosphorylation

Photosynthesis

Carbohydrate Structure and Function

Carbohydrate Metabolism

Lipid Structure and Function

Lipid Metabolism

Nucleotide Metabolism

Metabolic Integration

DNA Replication, Repair, and Recombination

RNA Synthesis, Processing, and Gene Silencing

Protein Synthesis, Posttranslational Modification, and Transport

Gene Regulation

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