Question 1

An amino acid whose R group is predominantly hydrocarbon would be classified as

Accepted Answer

A) polar. 
B) non-polar. 
C) basic. 
D) acidic. 
E) isoelectric. 
A) polar. 
B) non-polar. 
C) basic. 
D) acidic. 
E) isoelectric. B

Question 2

Which functional group is least important in biochemistry?

Accepted Answer

A) amide 
B) amine 
C) aromatic 
D) ester 
E) hydroxyl 
A) amide 
B) amine 
C) aromatic 
D) ester 
E) hydroxyl C

Question 3

Keratin,the protein of hair and skin,has extensive sections with which secondary structure?

Accepted Answer

A) beta-pleated sheet 
B) alpha-helix 
C) random coil 
D) alpha-beta 
A) beta-pleated sheet 
B) alpha-helix 
C) random coil 
D) alpha-beta B

Question 4

Which amino acid can form covalent sulfur-sulfur bonds?

Accepted Answer

A) cysteine 
B) glycine 
C) proline 
D) methionine 
E) phenylalanine 
A) cysteine 
B) glycine 
C) proline 
D) methionine 
E) phenylalanine

Question 5

The beta-pleated sheet is an example of

Accepted Answer

A) primary structure. 
B) secondary structure. 
C) tertiary structure. 
D) quaternary structure. 
E) none of the above 
A) primary structure. 
B) secondary structure. 
C) tertiary structure. 
D) quaternary structure. 
E) none of the above

Question 6

The amino acid sequence of a protein is known as its

Accepted Answer

A) primary structure. 
B) secondary structure. 
C) tertiary structure. 
D) quaternary structure. 
E) none of the above 
A) primary structure. 
B) secondary structure. 
C) tertiary structure. 
D) quaternary structure. 
E) none of the above

Question 7

The isoelectric point of an amino acid is

Accepted Answer

A) the pH at which it exists in the basic form. 
B) the pH at which it exists in the acid form. 
C) the pH at which it exists in the zwitterion form. 
D) the pH equal to its pKa. 
E) the pH equal to its pKb. 
A) the pH at which it exists in the basic form. 
B) the pH at which it exists in the acid form. 
C) the pH at which it exists in the zwitterion form. 
D) the pH equal to its pKa. 
E) the pH equal to its pKb.

Question 8

All of the following are globular proteins except

Accepted Answer

A) myosin. 
B) ribonuclease. 
C) hemoglobin. 
D) albumin. 
E) immunoglobulin. 
A) myosin. 
B) ribonuclease. 
C) hemoglobin. 
D) albumin. 
E) immunoglobulin.

Question 9

Which structure represents a zwitterion?

Accepted Answer

A) 
  
B) 
  
C) 
  
D) 
  
E) 
  
A) 
  
B) 
  
C) 
  
D) 
  
E)

Question 10

How many different tripeptides can be formed from one molecule each of the amino acids tyrosine,valine,and alanine?

Accepted Answer

A) 3 
B) 6 
C) 9 
D) 12 
E) 24 
A) 3 
B) 6 
C) 9 
D) 12 
E) 24

Question 11

Match the following.
-hydrophilic

Accepted Answer

A) a protein that produces only amino acids upon hydrolysis 
B) the form of an amino acid in which both the carboxyl group and the amine group are charged,but the overall molecule remains neutral 
C) a protein that is usually insoluble in water,is very tough,and has a long shape 
D) a carbon atom bonded to four different groups and therefore able to form enantiomers 
E) a protein with the tertiary structure in which it normally occurs in living systems
F)refers to R groups that do not interact readily with water because they are non-polar
G)a protein that is usually water soluble,having a hydrophilic exterior and hydrophobic interior,and an overall rounded shape
H)refers to R groups which form hydrogen bonds with water because of their polarity
I)a protein that produces amino acids and other biomolecules or inorganic substances upon hydrolysis 
A) a protein that produces only amino acids upon hydrolysis 
B) the form of an amino acid in which both the carboxyl group and the amine group are charged,but the overall molecule remains neutral 
C) a protein that is usually insoluble in water,is very tough,and has a long shape 
D) a carbon atom bonded to four different groups and therefore able to form enantiomers 
E) a protein with the tertiary structure in which it normally occurs in living systems
F)refers to R groups that do not interact readily with water because they are non-polar
G)a protein that is usually water soluble,having a hydrophilic exterior and hydrophobic interior,and an overall rounded shape
H)refers to R groups which form hydrogen bonds with water because of their polarity
I)a protein that produces amino acids and other biomolecules or inorganic substances upon hydrolysis

Question 12

An amino acid will have the form shown at

Accepted Answer

A) a pH of 7.0. 
B) any pH other than 7.0. 
C) a pH greater than its isoelectric point. 
D) its isoelectric point. 
E) a pH less than its isoelectric point. 
A) a pH of 7.0. 
B) any pH other than 7.0. 
C) a pH greater than its isoelectric point. 
D) its isoelectric point. 
E) a pH less than its isoelectric point.

Question 13

All of the following can denature proteins without hydrolysis except

Accepted Answer

A) heat. 
B) mechanical stress. 
C) enzyme treatment. 
D) lowering of pH. 
E) heavy metal ions. 
A) heat. 
B) mechanical stress. 
C) enzyme treatment. 
D) lowering of pH. 
E) heavy metal ions.

Question 14

Non-polar R groups on amino acids are said to be ________ because they are not attracted to water molecules.

Accepted Answer

A) hydrophilic 
B) hydrophobic 
C) ionized 
D) unreactive 
E) none of these 
A) hydrophilic 
B) hydrophobic 
C) ionized 
D) unreactive 
E) none of these

Question 15

An amino acid has the form shown at

Accepted Answer

A) a pH of 7.0. 
B) any pH other than 7.0. 
C) a pH greater than its isoelectric point. 
D) its isoelectric point. 
E) a pH less than its isoelectric point. 
A) a pH of 7.0. 
B) any pH other than 7.0. 
C) a pH greater than its isoelectric point. 
D) its isoelectric point. 
E) a pH less than its isoelectric point.

Question 16

The reaction of amino acids to give peptides involves which pair of functional groups?

Accepted Answer

A) two amino groups 
B) two carboxyl groups 
C) an amino and a carboxyl group 
D) a carboxyl and an alcohol group 
A) two amino groups 
B) two carboxyl groups 
C) an amino and a carboxyl group 
D) a carboxyl and an alcohol group

Question 17

The pH at which the positive and negative charges of an amino acid balance each other is called the

Accepted Answer

A) isoelectric point. 
B) isobaric point. 
C) isobestic point. 
D) isotonic point. 
E) isomer point. 
A) isoelectric point. 
B) isobaric point. 
C) isobestic point. 
D) isotonic point. 
E) isomer point.

Question 18

Which molecule is chiral?

Accepted Answer

A) CH3OH 
B) CH3CH2OH 
C) CH2Cl2 
D) CHCl2Br 
E) CHFClBr 
A) CH3OH 
B) CH3CH2OH 
C) CH2Cl2 
D) CHCl2Br 
E) CHFClBr

Question 19

All of the following can be classified as biomolecules except

Accepted Answer

A) carbohydrates. 
B) proteins. 
C) lipids. 
D) nucleic acids. 
E) All of the above are biomolecules. 
A) carbohydrates. 
B) proteins. 
C) lipids. 
D) nucleic acids. 
E) All of the above are biomolecules.

Question 20

Amino acids found in proteins all have the following features:

Accepted Answer

A) All are α-amino acids. 
B) All are L-amino acids. 
C) All are D- amino acids. 
D) All are correct. 
E) None are correct. 
A) All are α-amino acids. 
B) All are L-amino acids. 
C) All are D- amino acids. 
D) All are correct. 
E) None are correct.

Exam 18: Amino Acids and Proteins

An amino acid whose R group is predominantly hydrocarbon would be classified as

Which functional group is least important in biochemistry?

Keratin,the protein of hair and skin,has extensive sections with which secondary structure?

Which amino acid can form covalent sulfur-sulfur bonds?

The beta-pleated sheet is an example of

The amino acid sequence of a protein is known as its

The isoelectric point of an amino acid is

All of the following are globular proteins except

Which structure represents a zwitterion?

How many different tripeptides can be formed from one molecule each of the amino acids tyrosine,valine,and alanine?

Match the following. -hydrophilic

An amino acid will have the form shown at

All of the following can denature proteins without hydrolysis except

Non-polar R groups on amino acids are said to be ________ because they are not attracted to water molecules.

An amino acid has the form shown at

The reaction of amino acids to give peptides involves which pair of functional groups?

The pH at which the positive and negative charges of an amino acid balance each other is called the

Which molecule is chiral?

All of the following can be classified as biomolecules except

Amino acids found in proteins all have the following features:

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

Enzymes and Vitamins

The Generation of Biochemical Energy

Carbohydrates

Carbohydrate Metabolism

Lipids

Lipid Metabolism

Nucleic Acids and Protein Synthesis

Genomics

Protein and Amino Acid Metabolism

Chemical Messengers: Hormones, neurotransmitters, and Drugs

Body Fluids

Filters