Question 1

The structural formula of urea is ________.

Accepted Answer

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

Question 2

Complementary sources of protein are

Accepted Answer

A) single foods that contain all of the essential amino acids. 
B) single foods that contain all of the nonessential amino acids. 
C) single foods that contain none of the essential amino acids. 
D) single foods that contain none of the nonessential amino acids. 
E) combinations of foods that provide all of the amino acids,both essential and nonessential. 
A) single foods that contain all of the essential amino acids. 
B) single foods that contain all of the nonessential amino acids. 
C) single foods that contain none of the essential amino acids. 
D) single foods that contain none of the nonessential amino acids. 
E) combinations of foods that provide all of the amino acids,both essential and nonessential.

Question 3

An essential amino acid is one that

Accepted Answer

A) is required for the synthesis of all proteins. 
B) must be obtained in the diet because the human body cannot synthesize it. 
C) can safely be omitted from the diet because the human body can produce it in unlimited amounts. 
D) must be provided in the diet for individuals with specific hereditary enzyme deficiencies. 
E) has a relatively simple carbon skeleton. 
A) is required for the synthesis of all proteins. 
B) must be obtained in the diet because the human body cannot synthesize it. 
C) can safely be omitted from the diet because the human body can produce it in unlimited amounts. 
D) must be provided in the diet for individuals with specific hereditary enzyme deficiencies. 
E) has a relatively simple carbon skeleton.

Question 4

Which of the following types of compounds do not require nitrogen for their biosynthesis?

Accepted Answer

A) purines 
B) pyrimidines 
C) neurotransmitters 
D) urea 
E) All of these require nitrogen. 
A) purines 
B) pyrimidines 
C) neurotransmitters 
D) urea 
E) All of these require nitrogen.

Question 5

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 6

One of the most important functions of amino acids is for the synthesis of

Accepted Answer

A) glucose. 
B) pyruvate for energy. 
C) body proteins. 
D) purines and pyrimidines. 
A) glucose. 
B) pyruvate for energy. 
C) body proteins. 
D) purines and pyrimidines.

Question 7

Match the following.
-glucogenic amino acid

Accepted Answer

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

Question 8

In the anabolism of amino acids,________ is the source of the amine group.

Accepted Answer

A) aspartate 
B) urea 
C) glutamate 
D) arginine 
E) phenylalanine 
A) aspartate 
B) urea 
C) glutamate 
D) arginine 
E) phenylalanine

Question 9

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 10

Which of the following processes is important when new amino acids are produced in the body?

Accepted Answer

A) deamination 
B) transamination 
C) urea cycle 
D) phosphorylation 
A) deamination 
B) transamination 
C) urea cycle 
D) phosphorylation

Question 11

Match the following.
-amino acid pool

Accepted Answer

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

Question 12

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

Question 13

Which is the correct order for the steps in digestion and absorption of proteins?
I.hydrolysis by pancreatic lipases
II.denaturation by stomach acid
III.hydrolysis by pepsin
IV.active transport into the bloodstream

Accepted Answer

A) I,II,III,IV 
B) IV,II,III,I 
C) II,I,III,IV 
D) II,III,I,IV 
E) III,II,IV,I 
A) I,II,III,IV 
B) IV,II,III,I 
C) II,I,III,IV 
D) II,III,I,IV 
E) III,II,IV,I

Question 14

Glucogenic amino acids can be converted into which of the following?

Accepted Answer

A) glucose 
B) fatty acids 
C) acetyl CoA 
D) ketone bodies 
E) They can be converted into all of the above. 
A) glucose 
B) fatty acids 
C) acetyl CoA 
D) ketone bodies 
E) They can be converted into all of the above.

Question 15

The source of nitrogen for the synthesis of nonessential amino acids is

Accepted Answer

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

Question 16

What percentage of a healthy adult's energy need is met by metabolism of protein?

Accepted Answer

A) less than 5 
B) 10-20 
C) 35-45 
D) 65-75 
E) more than 90 
A) less than 5 
B) 10-20 
C) 35-45 
D) 65-75 
E) more than 90

Question 17

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 18

Match the following.
-essential amino acid

Accepted Answer

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

Question 19

The enzyme that removes an amine group from an amino acid and moves it to α-ketoglutarate is classified as a

Accepted Answer

A) ligase. 
B) phosphatase. 
C) transaminase. 
D) dehydrogenase. 
E) kinase. 
A) ligase. 
B) phosphatase. 
C) transaminase. 
D) dehydrogenase. 
E) kinase.

Question 20

PKU,phenylketonuria,is caused by a defect in the enzyme that converts

Accepted Answer

A) alanine to serine. 
B) phenylalanine to tyrosine. 
C) tryptophan to tyrosine. 
D) alanine to phenylalanine. 
A) alanine to serine. 
B) phenylalanine to tyrosine. 
C) tryptophan to tyrosine. 
D) alanine to phenylalanine.

Exam 27: Protein and Amino Acid Metabolism

The structural formula of urea is ________.

Complementary sources of protein are

An essential amino acid is one that

Which of the following types of compounds do not require nitrogen for their biosynthesis?

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

One of the most important functions of amino acids is for the synthesis of

Match the following. -glucogenic amino acid

In the anabolism of amino acids,________ is the source of the amine group.

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

Which of the following processes is important when new amino acids are produced in the body?

Match the following. -amino acid pool

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

Which is the correct order for the steps in digestion and absorption of proteins? I.hydrolysis by pancreatic lipases II.denaturation by stomach acid III.hydrolysis by pepsin IV.active transport into the bloodstream

Glucogenic amino acids can be converted into which of the following?

The source of nitrogen for the synthesis of nonessential amino acids is

What percentage of a healthy adult's energy need is met by metabolism of protein?

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

Match the following. -essential amino acid

The enzyme that removes an amine group from an amino acid and moves it to α-ketoglutarate is classified as a

PKU,phenylketonuria,is caused by a defect in the enzyme that converts

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

Amines

Aldehydes and Ketones

Carboxylic Acids and Their Derivatives

Amino Acids and Proteins

Enzymes and Vitamins

The Generation of Biochemical Energy

Carbohydrates

Carbohydrate Metabolism

Lipids

Lipid Metabolism

Nucleic Acids and Protein Synthesis

Genomics

Chemical Messengers: Hormones, neurotransmitters, and Drugs

Body Fluids

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