Question 1

The alpha helix structure of a protein can be considered an example of:

Accepted Answer

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

Question 2

For lysine pK1 = 2.2, pK2 = 9.0 and pK3 = 10.5. Select the correct value for the isoelectric point

Accepted Answer

A)  2.2 
B)  5.6 
C)  9.0 
D)  9.75 
E)  10.50 
A)  2.2 
B)  5.6 
C)  9.0 
D)  9.75 
E)  10.50 D

Question 3

The beta-conformation structure of a protein can be considered 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 B

Question 4

All the following statements regarding elastin fibers are true EXCEPT they

Accepted Answer

A)  are comprised entirely of linked tropoelastin molecules. 
B)  are cross-linked by a system of aldehyde mediated bonds. 
C)  lose their tensile strength in copper deficiencies. 
D)  require the presence of desmosine and/or isodesmosine for mechanical function. 
A)  are comprised entirely of linked tropoelastin molecules. 
B)  are cross-linked by a system of aldehyde mediated bonds. 
C)  lose their tensile strength in copper deficiencies. 
D)  require the presence of desmosine and/or isodesmosine for mechanical function.

Question 5

A structural feature shared by all alpha-helices and all beta-sheets in proteins is

Accepted Answer

A)  covalent modification by phosphorylation. 
B)  cross links through disulfide bonds. 
C)  minimal exposure on the surface. 
D)  proteolytic digestion by trypsin. 
E)  stabilization by hydrogen bonds. 
A)  covalent modification by phosphorylation. 
B)  cross links through disulfide bonds. 
C)  minimal exposure on the surface. 
D)  proteolytic digestion by trypsin. 
E)  stabilization by hydrogen bonds.

Question 6

Which of the following groups contains amino acids with sidechains that are all strong absorbers of ultraviolet (UV) radiation?

Accepted Answer

A)  Glycine and alanine 
B)  Alanine and tyrosine 
C)  Tyrosine and tryptophan 
D)  Phenylalanine and lysine 
E)  Glutamic acid and lysine 
A)  Glycine and alanine 
B)  Alanine and tyrosine 
C)  Tyrosine and tryptophan 
D)  Phenylalanine and lysine 
E)  Glutamic acid and lysine

Question 7

Which of the following is not an example of secondary structure;

Accepted Answer

A)  Beta-pleated sheet 
B)  collagen triple helix 
C)  Alpha-helix 
D)  Beta-bend 
E)  disulfide bridge 
A)  Beta-pleated sheet 
B)  collagen triple helix 
C)  Alpha-helix 
D)  Beta-bend 
E)  disulfide bridge

Question 8

Each of the following statements about the side chains of amino acid residues is true EXCEPT which one?

Accepted Answer

A)  Isoleucine, valine and tryptophan tend to be in the interior of protein molecules. 
B)  Catalytically functional groups include aspartate, histidine and cysteine. 
C)  Tyrosine, phenylalanine and threonine participate in hydrogen bond formation. 
D)  Lysine, arginine and glutamate form ionic bonds with substrates and other protein components. 
E)  Lysine, cysteine and tyrosine have pKa's higher than 7.0. 
A)  Isoleucine, valine and tryptophan tend to be in the interior of protein molecules. 
B)  Catalytically functional groups include aspartate, histidine and cysteine. 
C)  Tyrosine, phenylalanine and threonine participate in hydrogen bond formation. 
D)  Lysine, arginine and glutamate form ionic bonds with substrates and other protein components. 
E)  Lysine, cysteine and tyrosine have pKa's higher than 7.0.

Question 9

Adding an organic solvent to a protein solution may cause all of the following EXCEPT which one?

Accepted Answer

A)  aggregation. 
B)  denaturation. 
C)  alteration of electrostatic interactions. 
D)  rupture of covalent bonds. 
E)  rupture of hydrophobic bonds. 
A)  aggregation. 
B)  denaturation. 
C)  alteration of electrostatic interactions. 
D)  rupture of covalent bonds. 
E)  rupture of hydrophobic bonds.

Question 10

At a pH more acidic than its isoelectric point, an amino acid will carry

Accepted Answer

A)  a net negative charge. 
B)  a net positive charge. 
C)  a positive charge equal to the negative charge. 
D)  no ionic charge. 
E)  an unknown charge, since its concentration is not specified. 
A)  a net negative charge. 
B)  a net positive charge. 
C)  a positive charge equal to the negative charge. 
D)  no ionic charge. 
E)  an unknown charge, since its concentration is not specified.

Question 11

The following is the structure of which amino acid? (CH3)2-CH-CH2-CHNH2-COOH

Accepted Answer

A)  isoleucine 
B)  threonine 
C)  arginine 
D)  valine 
E)  lysine 
A)  isoleucine 
B)  threonine 
C)  arginine 
D)  valine 
E)  lysine

Question 12

When a protein is hydrolyzed there is

Accepted Answer

A)  a decrease in free carboxyl groups. 
B)  an increase in free amino groups. 
C)  a large decrease in pH. 
D)  formation of peptide bonds. 
E)  a decrease in free amino groups. 
A)  a decrease in free carboxyl groups. 
B)  an increase in free amino groups. 
C)  a large decrease in pH. 
D)  formation of peptide bonds. 
E)  a decrease in free amino groups.

Question 13

The absorption spectrum of proteins has a peak at around 28 nm due to

Accepted Answer

A)  the peptide bonds. 
B)  hydrogen bonding. 
C)  disulfide bridges 
D)  aromatic amino acids. 
E)  serine and threonine. 
A)  the peptide bonds. 
B)  hydrogen bonding. 
C)  disulfide bridges 
D)  aromatic amino acids. 
E)  serine and threonine.

Question 14

Which of the following characterizes L-lysine?

Accepted Answer

A)  monoamino monocarboxylic amino acid 
B)  diamino monocarboxylic amino acid 
C)  monoamino dicarboxylic amino acid 
D)  aromatic amino acid 
E)  cyclic imino acid 
A)  monoamino monocarboxylic amino acid 
B)  diamino monocarboxylic amino acid 
C)  monoamino dicarboxylic amino acid 
D)  aromatic amino acid 
E)  cyclic imino acid

Question 15

An amino acid residue which forms a covalent link to sugar moieties in collagen is

Accepted Answer

A)  hydroxylysine. 
B)  proline. 
C)  lysine. 
D)  glycine. 
E)  desmosine. 
A)  hydroxylysine. 
B)  proline. 
C)  lysine. 
D)  glycine. 
E)  desmosine.

Question 16

Bonding attraction and repulsion are determined by the distance between the two bonding atoms. Which type of bonding includes a type of repulsion called steric hindrance?

Accepted Answer

A)  Covalent 
B)  Electrostatic 
C)  Hydrogen 
D)  Hydrophobic 
E)  Van der Waals 
A)  Covalent 
B)  Electrostatic 
C)  Hydrogen 
D)  Hydrophobic 
E)  Van der Waals

Question 17

Identify in the following list the covalent bond commonly found in proteins

Accepted Answer

A)  hydrogen bond. 
B)  hydrophobic bond. 
C)  pleated sheet. 
D)  electrostatic bond. 
E)  disulfide bond. 
A)  hydrogen bond. 
B)  hydrophobic bond. 
C)  pleated sheet. 
D)  electrostatic bond. 
E)  disulfide bond.

Question 18

The isoelectric pH of aspartic acid is about

Accepted Answer

A)  1.9 
B)  2.75 
C)  3.6 
D)  6.6 
E)  9.6 
A)  1.9 
B)  2.75 
C)  3.6 
D)  6.6 
E)  9.6

Question 19

Although there is an element of molecular size contributing to most electrophoresis separations, in which of the following types of media is it most influential?

Accepted Answer

A)  Paper. 
B)  Cellulose acetate. 
C)  Polyacrylamide gel. 
D)  Agar gel. 
A)  Paper. 
B)  Cellulose acetate. 
C)  Polyacrylamide gel. 
D)  Agar gel.

Question 20

Within the native tertiary structure of a typical globular protein, interactions between an alpha-helix and a beta_sheet would occur primarily

Accepted Answer

A)  after the incorporation of a prosthetic group during polypeptide folding. 
B)  by non-covalent interactions among the amino acid side chains. 
C)  following the hydrolysis of ATP. 
D)  in the presence of one or more chaperones. 
E)  near the ends of these structural conformations. 
A)  after the incorporation of a prosthetic group during polypeptide folding. 
B)  by non-covalent interactions among the amino acid side chains. 
C)  following the hydrolysis of ATP. 
D)  in the presence of one or more chaperones. 
E)  near the ends of these structural conformations.

Exam 3: Protein I: Composition and Structure

The alpha helix structure of a protein can be considered an example of:

For lysine pK1 = 2.2, pK2 = 9.0 and pK3 = 10.5. Select the correct value for the isoelectric point

The beta-conformation structure of a protein can be considered an example of

All the following statements regarding elastin fibers are true EXCEPT they

A structural feature shared by all alpha-helices and all beta-sheets in proteins is

Which of the following groups contains amino acids with sidechains that are all strong absorbers of ultraviolet (UV) radiation?

Which of the following is not an example of secondary structure;

Each of the following statements about the side chains of amino acid residues is true EXCEPT which one?

Adding an organic solvent to a protein solution may cause all of the following EXCEPT which one?

At a pH more acidic than its isoelectric point, an amino acid will carry

The following is the structure of which amino acid? (CH3)2-CH-CH2-CHNH2-COOH

When a protein is hydrolyzed there is

The absorption spectrum of proteins has a peak at around 28 nm due to

Which of the following characterizes L-lysine?

An amino acid residue which forms a covalent link to sugar moieties in collagen is

Bonding attraction and repulsion are determined by the distance between the two bonding atoms. Which type of bonding includes a type of repulsion called steric hindrance?

Identify in the following list the covalent bond commonly found in proteins

The isoelectric pH of aspartic acid is about

Although there is an element of molecular size contributing to most electrophoresis separations, in which of the following types of media is it most influential?

Within the native tertiary structure of a typical globular protein, interactions between an alpha-helix and a beta_sheet would occur primarily

Eukaryotic Cell Structure

DNA and RNA: Composition and Structure

DNA Replication, Recombination, and Repair

RNA: Transcription and Rna Processing

Protein Synthesis: Translation and Posttranslational Modifications

Recombinant Dna and Biotechnology

Regulation of Gene Expression

Protein II: Structure-Function Relationships in Protein Families

Enzymes: Classification, Kinetics, and Control

The Cytochromes P450 and Nitric Oxide Synthases

Biological Membranes: Structure and Membrane Transport

Fundamentals of Signal Transduction

Bioenergetics and Oxidative Metabolism

Carbohydrate Metabolism I: Major Metabolic Pathways and Their Control

Carbohydrate Metabolism II: Special Pathways and Glycoconjugates

Lipid Metabolism I: Synthesis, Storage, and Utilization of Fatty Acids and Triacylglycerols

Lipid Metabolism II: Pathways of Metabolism of Special Lipids

Amino Acid Metabolism

Purine and Pyrimidine Nucleotide Metabolism

Metabolic Interrelationships

Biochemistry of Hormones

Molecular Cell Biology

Cell Cycle, Programmed Cell Death, and Cancer

Digestion and Absorption of Basic Nutritional Constituents

Digestion and Absorption of Basic Nutritional Constituents

Principles of Nutrition I and II

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