Question 1

How many ATP are required for the production of two ammonia molecules (NH3) from one nitrogen molecule (N2)?

Accepted Answer

A)  2 ATP. 
B)  4 ATP. 
C)  8 ATP. 
D)  16 ATP. 
E)  32 ATP. 
A)  2 ATP. 
B)  4 ATP. 
C)  8 ATP. 
D)  16 ATP. 
E)  32 ATP.

Question 2

The ultimate end products of xanthine catabolsim are:

Accepted Answer

A)  two pyrimidines 
B)  urea and glyoxylate 
C)  uric acid 
D)  allantoin 
A)  two pyrimidines 
B)  urea and glyoxylate 
C)  uric acid 
D)  allantoin

Question 3

Which of the following is not associated with pyrimidine synthesis?

Accepted Answer

A)  Synthesis of the base while ribose is attached. 
B)  Stimulation of synthesis by purines. 
C)  An orotic acid intermediate. 
D)  Inhibition by pyrimidines. 
E)  All of these are features of pyrimidine synthesis. 
A)  Synthesis of the base while ribose is attached. 
B)  Stimulation of synthesis by purines. 
C)  An orotic acid intermediate. 
D)  Inhibition by pyrimidines. 
E)  All of these are features of pyrimidine synthesis.

Question 4

Some amino acids can only be made in small quantities in humans and must be supplemented in the diet in children or during repair of injured tissue.

Accepted Answer

A) True 
 B)False

Question 5

Essential amino acids cannot be synthesized in sufficient quantities within the human body.

Accepted Answer

A) True 
 B)False

Question 6

Enzymes which carry out one-carbon transfers can use any of these compounds, except :

Accepted Answer

A)  Biotin 
B)  Pyridoxal 
C)  Folic Acid 
D)  S -adenosylmethionine 
E)  All of these can carry out one-carbon transfers. 
A)  Biotin 
B)  Pyridoxal 
C)  Folic Acid 
D)  S -adenosylmethionine 
E)  All of these can carry out one-carbon transfers.

Question 7

Carbamoyl phosphate is made in both the mitochondria and the cytosol, because it is used in the synthesis of several different molecules which are made in either of the compartments.

Accepted Answer

A) True 
 B)False

Question 8

If an amino acid's degradation pathway leads to α -ketoglutarate, is it glucogenic?

Accepted Answer

A)  Yes. 
B)  No. 
C)  Only if the organism has a glyoxylate pathway. 
D)  Only if the organism does not have a glyoxylate pathway. 
A)  Yes. 
B)  No. 
C)  Only if the organism has a glyoxylate pathway. 
D)  Only if the organism does not have a glyoxylate pathway.

Question 9

Which of the following is not associated with purine synthesis?

Accepted Answer

A)  Synthesis of the base while ribose is attached. 
B)  Stimulation of ATP synthesis by GTP and of GTP synthesis by ATP 
C)  An Inosine intermediate. 
D)  Inhibition by pyrimidines. 
E)  All of these are features of purine synthesis. 
A)  Synthesis of the base while ribose is attached. 
B)  Stimulation of ATP synthesis by GTP and of GTP synthesis by ATP 
C)  An Inosine intermediate. 
D)  Inhibition by pyrimidines. 
E)  All of these are features of purine synthesis.

Question 10

​ Which of the following amino acids is both glucogenic and ketogenic?

Accepted Answer

A)  Phenylalanine 
B)  Asparagine 
C)  Methionine 
D)  Glutamine 
A)  Phenylalanine 
B)  Asparagine 
C)  Methionine 
D)  Glutamine

Question 11

Which of the following is not an intermediate in the urea cycle?

Accepted Answer

A)  arginine 
B)  citrulline 
C)  ornithine 
D)  lysine 
A)  arginine 
B)  citrulline 
C)  ornithine 
D)  lysine

Question 12

Folic acid is an important factor necessary for the production of three of the four deoxyribonucleotides needed for DNA synthesis. For which dNTP is this factor not necessary?

Accepted Answer

A)  dATP 
B)  dCTP 
C)  dGTP 
D)  dTTP 
A)  dATP 
B)  dCTP 
C)  dGTP 
D)  dTTP

Question 13

Which of the following amino acids is not glucogenic?

Accepted Answer

A)  Glycine. 
B)  Alanine. 
C)  Aspartic Acid. 
D)  Leucine. 
E)  All of these amino acids are glucogenic. 
A)  Glycine. 
B)  Alanine. 
C)  Aspartic Acid. 
D)  Leucine. 
E)  All of these amino acids are glucogenic.

Question 14

The nitrogen-fixing enzyme system, nitrogenase, is found exclusively in

Accepted Answer

A)  plants 
B)  bacteria 
C)  some viruses 
D)  eukaryotic organisms 
E)  mammals 
A)  plants 
B)  bacteria 
C)  some viruses 
D)  eukaryotic organisms 
E)  mammals

Question 15

Which of the following statements concerning arginine is true ?

Accepted Answer

A)  Arginine is only marginally an essential amino acid, since it is made in the urea cycle. 
B)  Aspartic acid is the main amino acid precursor for the carbon chain in arginine. 
C)  Lysine could substitute for arginine as a dietary source for arginine. 
D)  Arginine is only essential in adults. 
A)  Arginine is only marginally an essential amino acid, since it is made in the urea cycle. 
B)  Aspartic acid is the main amino acid precursor for the carbon chain in arginine. 
C)  Lysine could substitute for arginine as a dietary source for arginine. 
D)  Arginine is only essential in adults.

Question 16

A metabolic intermediate that is not a precursor for an amino acid family is

Accepted Answer

A)  α -ketoglutarate 
B)  pyruvate 
C)  glyceraldehyde-3-phosphate 
D)  oxaloacetate 
A)  α -ketoglutarate 
B)  pyruvate 
C)  glyceraldehyde-3-phosphate 
D)  oxaloacetate

Question 17

In nitrogen fixation, the chemical change is

Accepted Answer

A)  NH4+ to NO2 −  
B)  NO3 −  to NH4+ 
C)  N2 to NH4+ or NH3 
D)  NO2 −  to N2 
E)  none of these 
A)  NH4+ to NO2 −  
B)  NO3 −  to NH4+ 
C)  N2 to NH4+ or NH3 
D)  NO2 −  to N2 
E)  none of these

Question 18

Which of the following is not true regarding ammonia and fertilizers?

Accepted Answer

A)  Ammonia gas is seldom an effective plant fertilizer, since it is usually consumed by the bacteria in the soil. 
B)  Many fertilizers are made from ammonia synthesized by the Haber process 
C)  Researchers are looking for ways to incorporate the genes for nitrogenase into crop plants so that not as much fertilizer is needed 
D)  Both ammonium and nitrate ions are frequently used in fertilizers 
A)  Ammonia gas is seldom an effective plant fertilizer, since it is usually consumed by the bacteria in the soil. 
B)  Many fertilizers are made from ammonia synthesized by the Haber process 
C)  Researchers are looking for ways to incorporate the genes for nitrogenase into crop plants so that not as much fertilizer is needed 
D)  Both ammonium and nitrate ions are frequently used in fertilizers

Question 19

The initial, common intermediate in purine catabolism for both AMP and GMP is

Accepted Answer

A)  xanthine 
B)  hypoxanthine 
C)  inosine 
D)  uric acid 
A)  xanthine 
B)  hypoxanthine 
C)  inosine 
D)  uric acid

Question 20

Nitrogen fixation in legumes may use as much as half of the ATP made in the plant.

Accepted Answer

A) True 
 B)False

Exam 23: The Metabolism of Nitrogen

How many ATP are required for the production of two ammonia molecules (NH3) from one nitrogen molecule (N2)?

The ultimate end products of xanthine catabolsim are:

Which of the following is not associated with pyrimidine synthesis?

Some amino acids can only be made in small quantities in humans and must be supplemented in the diet in children or during repair of injured tissue.

Essential amino acids cannot be synthesized in sufficient quantities within the human body.

Enzymes which carry out one-carbon transfers can use any of these compounds, except :

Carbamoyl phosphate is made in both the mitochondria and the cytosol, because it is used in the synthesis of several different molecules which are made in either of the compartments.

If an amino acid's degradation pathway leads to α -ketoglutarate, is it glucogenic?

Which of the following is not associated with purine synthesis?

​ Which of the following amino acids is both glucogenic and ketogenic?

Which of the following is not an intermediate in the urea cycle?

Folic acid is an important factor necessary for the production of three of the four deoxyribonucleotides needed for DNA synthesis. For which dNTP is this factor not necessary?

Which of the following amino acids is not glucogenic?

The nitrogen-fixing enzyme system, nitrogenase, is found exclusively in

Which of the following statements concerning arginine is true ?

A metabolic intermediate that is not a precursor for an amino acid family is

In nitrogen fixation, the chemical change is

Which of the following is not true regarding ammonia and fertilizers?

The initial, common intermediate in purine catabolism for both AMP and GMP is

Nitrogen fixation in legumes may use as much as half of the ATP made in the plant.

Biochemistry and the Organization of Cells

Water the Solvent for Biochemical Reactions

Amino Acids and Peptides

The Three Dimensional Structure of Proteins

Protein Purification and Characterization Techniques

The Behavior of Proteins Enzymes

The Behavior of Proteins Enzymes Mechanisms and Control

Lipids and Proteins Are Associated in Biological Membranes

Nucleic Acids How Structure Conveys Information

Biosynthesis of Nucleic Acids Replication

Transcription of the Genetic Code the Biosynthesis of Rna

Protein Synthesis Translation of the Genetic Message

Nucleic Acid Biotechnology Techniques

Viruses Cancer and Immunology

The Importance of Energy Changes and Electron Transfer in Metabolism

Carbohydrates

Glycolysis

Storage Mechanisms and Control in Carbohydrate Metabolism

The Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Lipid Metabolism

Photosynthesis

Integration of Metabolism Cellular Signaling

Filters

How many ATP are required for the production of two ammonia molecules (NH₃) from one nitrogen molecule (N₂)?

Which of the following amino acids is both glucogenic and ketogenic?