Question 1

Since the formation of ammonia is toxic to cells,the amino nitrogen from protein catabolism

Accepted Answer

A) can be excreted in the form of urea. 
B) can be used in the synthesis of nitrogen containing hormones. 
C) can be used in the synthesis of nucleic acids. 
D) all of the above 
E) none of the above 
A) can be excreted in the form of urea. 
B) can be used in the synthesis of nitrogen containing hormones. 
C) can be used in the synthesis of nucleic acids. 
D) all of the above 
E) none of the above

Question 2

The common features of catabolism of all amino acids include

Accepted Answer

A) removal of the amine group and conversion of the carbon skeleton to intermediates which can enter the citric acid cycle. 
B) hydrolysis of peptide linkages and production of CO2 as waste. 
C) hydrolysis of peptide linkages and production of urea as waste. 
D) diversion of the carbon skeletons into gluconeogenesis. 
E) diversion of the carbon skeletons into ketogenesis. 
A) removal of the amine group and conversion of the carbon skeleton to intermediates which can enter the citric acid cycle. 
B) hydrolysis of peptide linkages and production of CO2 as waste. 
C) hydrolysis of peptide linkages and production of urea as waste. 
D) diversion of the carbon skeletons into gluconeogenesis. 
E) diversion of the carbon skeletons into ketogenesis.

Question 3

The first step in amino acid catabolism is

Accepted Answer

A) transamination. 
B) decarboxylation. 
C) oxidation. 
D) esterification. 
E) tautomerization. 
A) transamination. 
B) decarboxylation. 
C) oxidation. 
D) esterification. 
E) tautomerization.

Question 4

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 5

The amino acid ________ is important in the formation of collagen and elastin.

Accepted Answer

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

Question 6

Which of the following amino acids is essential in growing children and in the repair of tissue?

Accepted Answer

A) arginine 
B) histidine 
C) glutamine 
D) lysine 
E) valine 
A) arginine 
B) histidine 
C) glutamine 
D) lysine 
E) valine

Question 7

The urea cycle is part of the metabolic breakdown of

Accepted Answer

A) amino acids. 
B) pyrimidines. 
C) purines. 
D) lipids. 
E) carbohydrates. 
A) amino acids. 
B) pyrimidines. 
C) purines. 
D) lipids. 
E) carbohydrates.

Question 8

Match the following.
-essential 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 9

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 10

Which pH range is the one where the enzymes trypsin and chymotrypsin are most active?

Accepted Answer

A) 1-2 
B) 3-4 
C) 5-6 
D) 7-8 
E) 9-10 
A) 1-2 
B) 3-4 
C) 5-6 
D) 7-8 
E) 9-10

Question 11

Which of the following enzymes is involved in protein digestion in the stomach?

Accepted Answer

A) trypsin 
B) pepsin 
C) chymotrypsin 
D) pepsinogen 
E) carboxypeptidase 
A) trypsin 
B) pepsin 
C) chymotrypsin 
D) pepsinogen 
E) carboxypeptidase

Question 12

Match the following.
-urea cycle

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 13

Define the terms
A)amino acid pool and
B)turnover for a protein

Accepted Answer

A) The amino acid pool is the

Question 14

Match the following.
-amino acid pool

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 15

The amino acid pool is the collection of

Accepted Answer

A) all amino acids available from the diet. 
B) amino acids produced from breakdown of proteins and available for reuse. 
C) essential amino acids available from the diet or from breakdown of other proteins. 
D) all free amino acids in the body. 
E) all amino acids in the body,whether free or part of proteins. 
A) all amino acids available from the diet. 
B) amino acids produced from breakdown of proteins and available for reuse. 
C) essential amino acids available from the diet or from breakdown of other proteins. 
D) all free amino acids in the body. 
E) all amino acids in the body,whether free or part of proteins.

Question 16

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 17

In the general process for amino acid catabolism,one of the steps involves

Accepted Answer

A) the use of the removed amino group in the synthesis of new nitrogen compounds. 
B) removal of the amino group. 
C) passage of the nitrogen into the urea cycle. 
D) all of these 
E) none of these 
A) the use of the removed amino group in the synthesis of new nitrogen compounds. 
B) removal of the amino group. 
C) passage of the nitrogen into the urea cycle. 
D) all of these 
E) none of these

Question 18

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 19

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 20

When glutamate acts as the source of an amino group,the enzyme involved is a

Accepted Answer

A) transferase. 
B) lipase. 
C) pepsin. 
D) synthetase. 
E) dehydrogenase. 
A) transferase. 
B) lipase. 
C) pepsin. 
D) synthetase. 
E) dehydrogenase.

Exam 25: Protein and Amino Acid Metabolism

Since the formation of ammonia is toxic to cells,the amino nitrogen from protein catabolism

The common features of catabolism of all amino acids include

The first step in amino acid catabolism is

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

The amino acid ________ is important in the formation of collagen and elastin.

Which of the following amino acids is essential in growing children and in the repair of tissue?

The urea cycle is part of the metabolic breakdown of

Match the following. -essential amino acid

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

Which pH range is the one where the enzymes trypsin and chymotrypsin are most active?

Which of the following enzymes is involved in protein digestion in the stomach?

Match the following. -urea cycle

Define the terms A)amino acid pool and B)turnover for a protein

Match the following. -amino acid pool

The amino acid pool is the collection of

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

In the general process for amino acid catabolism,one of the steps involves

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

Complementary sources of protein are

When glutamate acts as the source of an amino group,the enzyme involved is a

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