Question 1

The term denaturation, when used in connection with nucleic acids or proteins refers to a change in structural characteristics due to

Accepted Answer

A)  the disruption of covalent bonds. 
B)  the disruption of non-covalent bonds. 
C)  the binding of toxic compounds. 
D)  changes in primary structure. 
E)  changes in the state of aggregation. 
A)  the disruption of covalent bonds. 
B)  the disruption of non-covalent bonds. 
C)  the binding of toxic compounds. 
D)  changes in primary structure. 
E)  changes in the state of aggregation.

Question 2

Hemoglobin A differs from hemoglobin S in having two more anionic groups (both hemoglobins have a molecular weight of approximately 67,000). Which one of the following separation methods is most likely to distinguish between these two hemoglobins?

Accepted Answer

A)  Precipitation with ethanol 
B)  Gel filtration 
C)  Ultracentrifugation 
D)  Electrophoresis 
A)  Precipitation with ethanol 
B)  Gel filtration 
C)  Ultracentrifugation 
D)  Electrophoresis

Question 3

Which of the following amino acids will terminate an alpha helical structure in globular proteins?

Accepted Answer

A)  Tryptophan 
B)  Proline 
C)  Tyrosine 
D)  Histidine 
E)  Isoleucine 
A)  Tryptophan 
B)  Proline 
C)  Tyrosine 
D)  Histidine 
E)  Isoleucine

Question 4

All of the following statements about the alpha-helix are true EXCEPT:

Accepted Answer

A)  the alpha-helix is right-handed. 
B)  there are 3.6 amino acids per turn of the alpha-helix. 
C)  the R groups of the amino acids are externally directed. 
D)  the alpha-helix is stabilized primarily by hydrophobic interactions. 
E)  the structure of the alpha-helix was predicted before it was observed in a protein 
A)  the alpha-helix is right-handed. 
B)  there are 3.6 amino acids per turn of the alpha-helix. 
C)  the R groups of the amino acids are externally directed. 
D)  the alpha-helix is stabilized primarily by hydrophobic interactions. 
E)  the structure of the alpha-helix was predicted before it was observed in a protein

Question 5

What is the definition of tertiary protein structure?

Accepted Answer

A)  a-helices and b-pleated sheets 
B)  Interaction between subunits 
C)  Location of each atom in space 
D)  Location of water in the interior 
E)  Number of domains 
A)  a-helices and b-pleated sheets 
B)  Interaction between subunits 
C)  Location of each atom in space 
D)  Location of water in the interior 
E)  Number of domains

Question 6

All of the following properties are common to fibrous proteins that occur in man EXCEPT which one?

Accepted Answer

A)  Insolubility or low solubility in water. 
B)  Readily hydrolyzed by digestive enzyme. 
C)  High tensile strength. 
D)  High content of proline and hydroxyproline. 
E)  Widely distributed in the animal body. 
A)  Insolubility or low solubility in water. 
B)  Readily hydrolyzed by digestive enzyme. 
C)  High tensile strength. 
D)  High content of proline and hydroxyproline. 
E)  Widely distributed in the animal body.

Question 7

At the isoionic point

Accepted Answer

A)  proteins are least soluble. 
B)  the net ionic charge is zero. 
C)  repulsive forces between proteins are at a minimum. 
D)  the pH of the solution may vary widely from protein to protein. 
E)  all of the above 
A)  proteins are least soluble. 
B)  the net ionic charge is zero. 
C)  repulsive forces between proteins are at a minimum. 
D)  the pH of the solution may vary widely from protein to protein. 
E)  all of the above

Question 8

Collagens are found in different types in the human body. These types are classified on the basis of

Accepted Answer

A)  ability to form triple helices. 
B)  glycine content. 
C)  hydroxyproline content. 
D)  modification by carbohydrate groups. 
E)  primary sequence of the procollagen polypeptides. 
A)  ability to form triple helices. 
B)  glycine content. 
C)  hydroxyproline content. 
D)  modification by carbohydrate groups. 
E)  primary sequence of the procollagen polypeptides.

Question 9

Determination of the molecular weight of a protein by the Svedberg equation requires which of the following terms?

Accepted Answer

A)  Svedberg coefficient 
B)  partial specific volume of the protein 
C)  diffusion coefficient 
D)  temperature in degrees Kelvin 
E)  all of the above 
A)  Svedberg coefficient 
B)  partial specific volume of the protein 
C)  diffusion coefficient 
D)  temperature in degrees Kelvin 
E)  all of the above

Question 10

In N-linked or type 1 glycoproteins, the linkage between the protein and the oligosaccharide is to which of the following amino acid residues?

Accepted Answer

A)  serine 
B)  threonine 
C)  lysine 
D)  hydroxylysine 
E)  asparagines 
A)  serine 
B)  threonine 
C)  lysine 
D)  hydroxylysine 
E)  asparagines

Question 11

The major interaction in which the side chain of serine could participate is

Accepted Answer

A)  hydrogen bonds. 
B)  charged dipoles. 
C)  hydrophobic interactions. 
D)  disulfide bridges. 
E)  secondary amide bonds. 
A)  hydrogen bonds. 
B)  charged dipoles. 
C)  hydrophobic interactions. 
D)  disulfide bridges. 
E)  secondary amide bonds.

Question 12

Information indicating that the final conformation of a protein is determined by the amino acid sequence in its polypeptide chains was obtained from

Accepted Answer

A)  difference spectroscopy. 
B)  reversible denaturation. 
C)  atomic adsorption. 
D)  hydrodynamic analysis. 
E)  sequence analysis. 
A)  difference spectroscopy. 
B)  reversible denaturation. 
C)  atomic adsorption. 
D)  hydrodynamic analysis. 
E)  sequence analysis.

Question 13

Each of two proteins has a single chain with no disulfide bonds. If they have the same molecular weight and amino acid composition, then it is most likely that they have the same

Accepted Answer

A)  amino acid sequence. 
B)  sedimentation coefficient. 
C)  set of peptides produced by hydrolysis with trypsin. 
D)  3-D structure. 
E)  electrophoretic mobility in the presence of SDS. 
A)  amino acid sequence. 
B)  sedimentation coefficient. 
C)  set of peptides produced by hydrolysis with trypsin. 
D)  3-D structure. 
E)  electrophoretic mobility in the presence of SDS.

Question 14

All of the following are involved in the determination of the amino acid sequence in a protein EXCEPT

Accepted Answer

A)  determination of the number of polypeptide chains. 
B)  determination of extent of hydrogen bonding in the protein. 
C)  separation of individual polypeptide chains. 
D)  cleavage of pure polypeptide chains to smaller chains. 
E)  determination of the sequence of amino aids in smaller products. 
A)  determination of the number of polypeptide chains. 
B)  determination of extent of hydrogen bonding in the protein. 
C)  separation of individual polypeptide chains. 
D)  cleavage of pure polypeptide chains to smaller chains. 
E)  determination of the sequence of amino aids in smaller products.

Question 15

In a simple protein molecule in aqueous solution, the charged groups

Accepted Answer

A)  are almost all on the surface. 
B)  are mostly engaged in intramolecular electrostatic bonds. 
C)  are completely accounted for by the side chains of the basic and acidic amino acids. 
D)  have pK's below the solution pH. 
E)  all of the above 
A)  are almost all on the surface. 
B)  are mostly engaged in intramolecular electrostatic bonds. 
C)  are completely accounted for by the side chains of the basic and acidic amino acids. 
D)  have pK's below the solution pH. 
E)  all of the above

Question 16

The amino acid side-chain which most commonly interacts to form covalent bonds in proteins

Accepted Answer

A)  contains an amino group. 
B)  can form an ester with an alcohol. 
C)  contains a sulfhydryl group. 
D)  is that of histidine. 
E)  is that of glutamate. 
A)  contains an amino group. 
B)  can form an ester with an alcohol. 
C)  contains a sulfhydryl group. 
D)  is that of histidine. 
E)  is that of glutamate.

Question 17

The hydrophobic effect is generally thought to be the result of:

Accepted Answer

A)  minimization of the disruption of the normal structure of water by hydrophobic molecules. 
B)  repulsive forces between polar water and nonpolar hydrophobic molecules. 
C)  maximization of order in the mixture of water and hydrophobic molecules. 
D)  all of the above 
E)  none of the above 
A)  minimization of the disruption of the normal structure of water by hydrophobic molecules. 
B)  repulsive forces between polar water and nonpolar hydrophobic molecules. 
C)  maximization of order in the mixture of water and hydrophobic molecules. 
D)  all of the above 
E)  none of the above

Question 18

The alpha-helix

Accepted Answer

A)  has hydrogen bonds that are perpendicular to the axis of the helix. 
B)  has 3.6 amino acid residues per turn. 
C)  is made up chiefly of proline or hydroxy proline residues. 
D)  All of the above are true. 
E)  Only two of the above are true. 
A)  has hydrogen bonds that are perpendicular to the axis of the helix. 
B)  has 3.6 amino acid residues per turn. 
C)  is made up chiefly of proline or hydroxy proline residues. 
D)  All of the above are true. 
E)  Only two of the above are true.

Question 19

In X-ray crystallography, the atoms which can diffract X-rays and thus be located within 3-dimensional space are the following EXCEPT for

Accepted Answer

A)  hydrogen 
B)  carbon 
C)  nitrogen 
D)  oxygen 
E)  sulfur 
A)  hydrogen 
B)  carbon 
C)  nitrogen 
D)  oxygen 
E)  sulfur

Question 20

The isoelectric point of arginine is approximately

Accepted Answer

A)  1 
B)  3 
C)  5 
D)  7 
E)  11 
A)  1 
B)  3 
C)  5 
D)  7 
E)  11

Exam 3: Protein I: Composition and Structure

The term denaturation, when used in connection with nucleic acids or proteins refers to a change in structural characteristics due to

Hemoglobin A differs from hemoglobin S in having two more anionic groups (both hemoglobins have a molecular weight of approximately 67,000). Which one of the following separation methods is most likely to distinguish between these two hemoglobins?

Which of the following amino acids will terminate an alpha helical structure in globular proteins?

All of the following statements about the alpha-helix are true EXCEPT:

What is the definition of tertiary protein structure?

All of the following properties are common to fibrous proteins that occur in man EXCEPT which one?

At the isoionic point

Collagens are found in different types in the human body. These types are classified on the basis of

Determination of the molecular weight of a protein by the Svedberg equation requires which of the following terms?

In N-linked or type 1 glycoproteins, the linkage between the protein and the oligosaccharide is to which of the following amino acid residues?

The major interaction in which the side chain of serine could participate is

Information indicating that the final conformation of a protein is determined by the amino acid sequence in its polypeptide chains was obtained from

Each of two proteins has a single chain with no disulfide bonds. If they have the same molecular weight and amino acid composition, then it is most likely that they have the same

All of the following are involved in the determination of the amino acid sequence in a protein EXCEPT

In a simple protein molecule in aqueous solution, the charged groups

The amino acid side-chain which most commonly interacts to form covalent bonds in proteins

The hydrophobic effect is generally thought to be the result of:

The alpha-helix

In X-ray crystallography, the atoms which can diffract X-rays and thus be located within 3-dimensional space are the following EXCEPT for

The isoelectric point of arginine is approximately

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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