Question 1

When the amino acid alanine is deaminated,it is converted to

Accepted Answer

A) glutamate. 
B) acetate. 
C) pyruvate. 
D) oxaloacetate. 
E) urea. 
A) glutamate. 
B) acetate. 
C) pyruvate. 
D) oxaloacetate. 
E) urea.

Question 2

Which statement best summarizes the digestion of proteins?

Accepted Answer

A) Amine groups are removed from all amino acids. 
B) All peptide linkages are hydrolyzed to produce a mixture of amino acids. 
C) Proteins are denatured by stomach acid. 
D) Amino acids are combined to produce proteins or enzymes. 
E) none of the above 
A) Amine groups are removed from all amino acids. 
B) All peptide linkages are hydrolyzed to produce a mixture of amino acids. 
C) Proteins are denatured by stomach acid. 
D) Amino acids are combined to produce proteins or enzymes. 
E) none of the above

Question 3

What is the structural formula of urea?

Accepted Answer

A) 
  
B)  NH4+ 
C) 
  
D) 
  
E) 
  
A) 
  
B)  NH4+ 
C) 
  
D) 
  
E)

Question 4

Which of the following common metabolites may be precursors for the synthesis of nonessential amino acids?

Accepted Answer

A) pyruvate 
B) oxaloacetate 
C) 3-phosphoglycerate 
D) α-ketoglutarate 
E) All of these may be used. 
A) pyruvate 
B) oxaloacetate 
C) 3-phosphoglycerate 
D) α-ketoglutarate 
E) All of these may be used.

Question 5

All of the following chemicals are part of the urea cycle except

Accepted Answer

A) carbamoyl phosphate. 
B) citrulline. 
C) arginine. 
D) fumarate. 
E) acetyl-CoA. 
A) carbamoyl phosphate. 
B) citrulline. 
C) arginine. 
D) fumarate. 
E) acetyl-CoA.

Question 6

Amino acids that can be synthesized in the body are called ________ amino acids.

Accepted Answer

A) essential 
B) glycogenic 
C) ketogenic 
D) nonessential 
A) essential 
B) glycogenic 
C) ketogenic 
D) nonessential

Question 7

The process of oxidative deamination of an amino acid produces which of the following?

Accepted Answer

A) urea 
B) CO2 and H2O 
C) NH4+ 
D) aspartate 
E) glutamate 
A) urea 
B) CO2 and H2O 
C) NH4+ 
D) aspartate 
E) glutamate

Question 8

The urea cycle is ________ because it ________.

Accepted Answer

A) exergonic;costs 3 ATP 
B) exergonic;releases 3 ATP 
C) endergonic;costs 3 ATP 
D) endergonic;releases 3 ATP 
E) neither exergonic nor endergonic;consumes 3 ATP in an early step and releases 3 ATP in a later step 
A) exergonic;costs 3 ATP 
B) exergonic;releases 3 ATP 
C) endergonic;costs 3 ATP 
D) endergonic;releases 3 ATP 
E) neither exergonic nor endergonic;consumes 3 ATP in an early step and releases 3 ATP in a later step

Question 9

All of the carbon backbones from amino acids end up as intermediates in the

Accepted Answer

A) citric acid cycle. 
B) urea cycle. 
C) β-oxidation sequence. 
D) both A and C 
E) none of the above 
A) citric acid cycle. 
B) urea cycle. 
C) β-oxidation sequence. 
D) both A and C 
E) none of the above

Question 10

Match the following.
-transamination

Accepted Answer

A) an amino acid whose carbon skeleton can be converted to a citric acid cycle intermediate,that ultimately becomes glucose 
B) an amino acid whose carbon skeleton can be converted to a citric acid cycle intermediate that later becomes a ketone body or a fatty acid 
C) the biochemical pathway that converts nitrogen and its derivatives to a less toxic form for excretion 
D) an amino acid which can be synthesized by the human body as needed 
E) the collection of all the free amino acids in the body
F)the transfer of an amine group from an amino acid to an α-keto acid
G)an amino acid that must be obtained in the diet because humans do not have the appropriate anabolic pathways for its synthesis 
A) an amino acid whose carbon skeleton can be converted to a citric acid cycle intermediate,that ultimately becomes glucose 
B) an amino acid whose carbon skeleton can be converted to a citric acid cycle intermediate that later becomes a ketone body or a fatty acid 
C) the biochemical pathway that converts nitrogen and its derivatives to a less toxic form for excretion 
D) an amino acid which can be synthesized by the human body as needed 
E) the collection of all the free amino acids in the body
F)the transfer of an amine group from an amino acid to an α-keto acid
G)an amino acid that must be obtained in the diet because humans do not have the appropriate anabolic pathways for its synthesis

Question 11

α-ketoacids are produced as a result of a transamination reaction with ________ acting as the donor molecule.

Accepted Answer

A) glutamate 
B) aspartate 
C) urea 
D) ornithine 
E) oxaloacetate 
A) glutamate 
B) aspartate 
C) urea 
D) ornithine 
E) oxaloacetate

Question 12

The structural formula of glutamate is

Accepted Answer

A) 
 
. 
B) NH4+. 
C) 
 
. 
D) 
 
. 
E) 
 
. 
A) 
 
. 
B) NH4+. 
C) 
 
. 
D) 
 
. 
E) 
 
.

Question 13

The reaction of pyruvate with glutamate is the main synthetic route for the formation of

Accepted Answer

A) aspartate. 
B) alanine. 
C) phenylalanine. 
D) glycine. 
E) α-ketoglutarate. 
A) aspartate. 
B) alanine. 
C) phenylalanine. 
D) glycine. 
E) α-ketoglutarate.

Question 14

α-ketoglutarate is converted to glutamate by

Accepted Answer

A) loss of a carbonyl group. 
B) loss of a carboxyl group. 
C) accepting an acetyl group. 
D) loss of an amide linkage. 
E) accepting an amine group. 
A) loss of a carbonyl group. 
B) loss of a carboxyl group. 
C) accepting an acetyl group. 
D) loss of an amide linkage. 
E) accepting an amine group.

Question 15

Match the following.
-glucogenic amino acid

Accepted Answer

A) an amino acid whose carbon skeleton can be converted to a citric acid cycle intermediate,that ultimately becomes glucose 
B) an amino acid whose carbon skeleton can be converted to a citric acid cycle intermediate that later becomes a ketone body or a fatty acid 
C) the biochemical pathway that converts nitrogen and its derivatives to a less toxic form for excretion 
D) an amino acid which can be synthesized by the human body as needed 
E) the collection of all the free amino acids in the body
F)the transfer of an amine group from an amino acid to an α-keto acid
G)an amino acid that must be obtained in the diet because humans do not have the appropriate anabolic pathways for its synthesis 
A) an amino acid whose carbon skeleton can be converted to a citric acid cycle intermediate,that ultimately becomes glucose 
B) an amino acid whose carbon skeleton can be converted to a citric acid cycle intermediate that later becomes a ketone body or a fatty acid 
C) the biochemical pathway that converts nitrogen and its derivatives to a less toxic form for excretion 
D) an amino acid which can be synthesized by the human body as needed 
E) the collection of all the free amino acids in the body
F)the transfer of an amine group from an amino acid to an α-keto acid
G)an amino acid that must be obtained in the diet because humans do not have the appropriate anabolic pathways for its synthesis

Question 16

The amino acid ________ plays a role in the absorption of calcium and formation of collagen for bones.

Accepted Answer

A) phenylalanine 
B) methionine 
C) lysine 
D) isoleucine 
E) histidine 
A) phenylalanine 
B) methionine 
C) lysine 
D) isoleucine 
E) histidine

Question 17

Each of the following metabolic intermediates is a precursor to one or more amino acids except

Accepted Answer

A) fumarate. 
B) α-ketoglutarate. 
C) oxaloacetate. 
D) 3-phosphoglycerate. 
E) pyruvate. 
A) fumarate. 
B) α-ketoglutarate. 
C) oxaloacetate. 
D) 3-phosphoglycerate. 
E) pyruvate.

Question 18

One of the intermediates formed in the urea cycle is the protein amino acid

Accepted Answer

A) glutamate. 
B) ornithine. 
C) aspartate. 
D) arginine. 
E) citrulline. 
A) glutamate. 
B) ornithine. 
C) aspartate. 
D) arginine. 
E) citrulline.

Question 19

Which of the following is the usual reactant in the urea cycle?

Accepted Answer

A) NH4+ 
B) glutamate 
C) pyruvate 
D) carbamoyl phosphate 
E) CO2 
A) NH4+ 
B) glutamate 
C) pyruvate 
D) carbamoyl phosphate 
E) CO2

Question 20

When an amino group is transferred to α-ketoglutarate,one product is always

Accepted Answer

A) glycine. 
B) glutamate. 
C) aspartate. 
D) alanine. 
E) leucine. 
A) glycine. 
B) glutamate. 
C) aspartate. 
D) alanine. 
E) leucine.

Exam 25: Protein and Amino Acid Metabolism

When the amino acid alanine is deaminated,it is converted to

Which statement best summarizes the digestion of proteins?

What is the structural formula of urea?

Which of the following common metabolites may be precursors for the synthesis of nonessential amino acids?

All of the following chemicals are part of the urea cycle except

Amino acids that can be synthesized in the body are called ________ amino acids.

The process of oxidative deamination of an amino acid produces which of the following?

The urea cycle is ________ because it ________.

All of the carbon backbones from amino acids end up as intermediates in the

Match the following. -transamination

α-ketoacids are produced as a result of a transamination reaction with ________ acting as the donor molecule.

The structural formula of glutamate is

The reaction of pyruvate with glutamate is the main synthetic route for the formation of

α-ketoglutarate is converted to glutamate by

Match the following. -glucogenic amino acid

The amino acid ________ plays a role in the absorption of calcium and formation of collagen for bones.

Each of the following metabolic intermediates is a precursor to one or more amino acids except

One of the intermediates formed in the urea cycle is the protein amino acid

Which of the following is the usual reactant in the urea cycle?

When an amino group is transferred to α-ketoglutarate,one product is always

Matter and Measurements

Atoms and the Periodic Table

Ionic Compounds

Molecular Compounds

Classification and Balancing of Chemical Reactions

Chemical Reactions: Mole and Mass Relationships

Chemical Reactions: Energy, rates, and Equilibrium

Gases, liquids, and Solids

Solutions

Acids and Bases

Nuclear Chemistry

Introduction to Organic Chemistry: Alkanes

Alkenes, alkynes, and Aromatic Compounds

Some Compounds With Oxygen, sulfur, or a Halogen

Aldehydes and Ketones

Amines

Carboxylic Acids and Their Derivatives

Amino Acids and Proteins

Enzymes and Vitamins

Carbohydrates

The Generation of Biochemical Energy

Carbohydrate Metabolism

Lipids

Lipid Metabolism

Nucleic Acids and Protein Synthesis

Genomics

Chemical Messengers: Hormones, neurotransmitters, and Drugs

Body Fluids

Filters

The urea cycle is because it .