Question 1

The three dimensional structures of a protein is maintained by

Accepted Answer

A)  disulfide linkages. 
B)  hydrophobic bonds. 
C)  hydrogen bonds. 
D)  ionic bonds. 
E)  all of the above 
A)  disulfide linkages. 
B)  hydrophobic bonds. 
C)  hydrogen bonds. 
D)  ionic bonds. 
E)  all of the above

Question 2

The principal proteins of connective tissues are

Accepted Answer

A)  elastin and chondroitin. 
B)  albumin and collagen. 
C)  collagen and elastin. 
D)  collagen and collagenase. 
E)  hyaluronic acid and elastin. 
A)  elastin and chondroitin. 
B)  albumin and collagen. 
C)  collagen and elastin. 
D)  collagen and collagenase. 
E)  hyaluronic acid and elastin.

Question 3

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 4

All of the following statements are correct about lipoproteins EXCEPT

Accepted Answer

A)  they are a complex of protein, phospholipids and neutral lipids. 
B)  they are found in the plasma and cellular membrane. 
C)  they are covalent complexes of lipids and proteins. 
D)  the lipids and proteins are separable from one another by treatment with detergent. 
E)  most or all of the lipid can be removed from the protein by extraction with chloroform-methanol mixtures. 
A)  they are a complex of protein, phospholipids and neutral lipids. 
B)  they are found in the plasma and cellular membrane. 
C)  they are covalent complexes of lipids and proteins. 
D)  the lipids and proteins are separable from one another by treatment with detergent. 
E)  most or all of the lipid can be removed from the protein by extraction with chloroform-methanol mixtures.

Question 5

Which of the following amino acids would be considered the MOST polar?

Accepted Answer

A)  Alanine. 
B)  Proline. 
C)  Isoleucine. 
D)  Threonine. 
E)  Phenylalanine. 
A)  Alanine. 
B)  Proline. 
C)  Isoleucine. 
D)  Threonine. 
E)  Phenylalanine.

Question 6

The lipoprotein with the highest content of triglycerides is

Accepted Answer

A)  LDL. 
B)  VLDL. 
C)  IDL. 
D)  HDL. 
E)  chylomicrons. 
A)  LDL. 
B)  VLDL. 
C)  IDL. 
D)  HDL. 
E)  chylomicrons.

Question 7

Which of the following describes the side chain of serine?

Accepted Answer

A)  contains a sulfhydryl group 
B)  contains an alcoholic group 
C)  contains an aromatic ring 
D)  doesn't have a side chain 
E)  contains an acidic group 
A)  contains a sulfhydryl group 
B)  contains an alcoholic group 
C)  contains an aromatic ring 
D)  doesn't have a side chain 
E)  contains an acidic group

Question 8

In man, the serum lipoprotein with the highest cholesterol content is

Accepted Answer

A)  alpha-lipoprotein 
B)  beta-lipoprotein 
C)  pre-beta-lipoprotein 
D)  chylomicrons 
E)  pre-albumin 
A)  alpha-lipoprotein 
B)  beta-lipoprotein 
C)  pre-beta-lipoprotein 
D)  chylomicrons 
E)  pre-albumin

Question 9

Information about the secondary structures of a protein most reliably and unambiguously derives from

Accepted Answer

A)  complementary DNA analysis. 
B)  ion-exchange chromatography. 
C)  polyacrylamide gel electrophoresis. 
D)  ultraviolet spectroscopy. 
E)  x-ray crystallography. 
A)  complementary DNA analysis. 
B)  ion-exchange chromatography. 
C)  polyacrylamide gel electrophoresis. 
D)  ultraviolet spectroscopy. 
E)  x-ray crystallography.

Question 10

The polypeptide chains in alpha-keratins

Accepted Answer

A)  consist of long sections of alpha-helices. 
B)  are sometimes twisted together to form rope-like structures. 
C)  are held in a protein matrix by many disulfide bridges. 
D)  All of the above are true. 
E)  Only two of the above are true. 
A)  consist of long sections of alpha-helices. 
B)  are sometimes twisted together to form rope-like structures. 
C)  are held in a protein matrix by many disulfide bridges. 
D)  All of the above are true. 
E)  Only two of the above are true.

Question 11

A peptide bond

Accepted Answer

A)  contributes atoms to hydrophobic interactions. 
B)  exhibits unrestricted rotation around the C-N bond. 
C)  is formed between the side chains of Glu and Lys residues. 
D)  is planar and partially ionic. 
A)  contributes atoms to hydrophobic interactions. 
B)  exhibits unrestricted rotation around the C-N bond. 
C)  is formed between the side chains of Glu and Lys residues. 
D)  is planar and partially ionic.

Question 12

The major functional groups present in collagen which are directly involved in the formation of crosslinks are

Accepted Answer

A)  aldehydes derived from lysine. 
B)  aldehydes derived from hydroxyproline. 
C)  ketone bodies derived from hydroxyalanine. 
D)  Schiff bases involving proline and acetaldehyde. 
A)  aldehydes derived from lysine. 
B)  aldehydes derived from hydroxyproline. 
C)  ketone bodies derived from hydroxyalanine. 
D)  Schiff bases involving proline and acetaldehyde.

Question 13

Which of the following amino acids has more than one carboxyl group?

Accepted Answer

A)  Serine 
B)  Glutamic acid 
C)  Lysine 
D)  Alanine 
E)  Methionine 
A)  Serine 
B)  Glutamic acid 
C)  Lysine 
D)  Alanine 
E)  Methionine

Question 14

Which amino acid possesses a guanidinium group in the side chain?

Accepted Answer

A)  Arginine 
B)  Aspartate 
C)  Methionine 
D)  Leucine 
E)  Serine 
A)  Arginine 
B)  Aspartate 
C)  Methionine 
D)  Leucine 
E)  Serine

Question 15

Which one of the following is a characteristic of the amino acid composition of a protein having an isoelectric pH (pI) of 4?

Accepted Answer

A)  no neutral amino acids. 
B)  no basic amino acids. 
C)  no acidic amino acids. 
D)  more basic than acidic amino acids. 
E)  more acidic than basic amino acids. 
A)  no neutral amino acids. 
B)  no basic amino acids. 
C)  no acidic amino acids. 
D)  more basic than acidic amino acids. 
E)  more acidic than basic amino acids.

Question 16

Gly-Gln-Ser-Lys-Met-Thr-Asp-Asn-Tyr What is the net charge of this peptide at pH 7.0?

Accepted Answer

A)  +2 
B)  +1 
C)  0 
D)  -1 
E)  -2 
A)  +2 
B)  +1 
C)  0 
D)  -1 
E)  -2

Question 17

From the following list select an amino acid with a side chain having strong UV-absorbing power

Accepted Answer

A)  proline. 
B)  hydroxyproline. 
C)  tryptophan. 
D)  arginine. 
E)  asparagine. 
A)  proline. 
B)  hydroxyproline. 
C)  tryptophan. 
D)  arginine. 
E)  asparagine.

Question 18

To which amino acid does cysteine have the closest chemical resemblance?

Accepted Answer

A)  serine 
B)  alanine 
C)  aspartic acid 
D)  lysine 
E)  methionine 
A)  serine 
B)  alanine 
C)  aspartic acid 
D)  lysine 
E)  methionine

Question 19

Characteristics of disulfide bonds in proteins include all of the following EXCEPT

Accepted Answer

A)  they are an example of a post-translational modification. 
B)  they are common in proteins secreted from cells. 
C)  they may cross-link two polypeptides in a globular protein. 
D)  they may form with the assistance of a chaperone. 
E)  they may stabilize the alpha-helix conformation. 
A)  they are an example of a post-translational modification. 
B)  they are common in proteins secreted from cells. 
C)  they may cross-link two polypeptides in a globular protein. 
D)  they may form with the assistance of a chaperone. 
E)  they may stabilize the alpha-helix conformation.

Question 20

Which of the following secondary structures is not commonly seen in proteins?

Accepted Answer

A)  right handed alpha-helix 
B)  left handed alpha-helix 
C)  parallel beta-pleated sheet 
D)  antiparallel beta-pleated sheet 
E)  beta-bend 
A)  right handed alpha-helix 
B)  left handed alpha-helix 
C)  parallel beta-pleated sheet 
D)  antiparallel beta-pleated sheet 
E)  beta-bend

Exam 3: Protein I: Composition and Structure

The three dimensional structures of a protein is maintained by

The principal proteins of connective tissues are

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

All of the following statements are correct about lipoproteins EXCEPT

Which of the following amino acids would be considered the MOST polar?

The lipoprotein with the highest content of triglycerides is

Which of the following describes the side chain of serine?

In man, the serum lipoprotein with the highest cholesterol content is

Information about the secondary structures of a protein most reliably and unambiguously derives from

The polypeptide chains in alpha-keratins

A peptide bond

The major functional groups present in collagen which are directly involved in the formation of crosslinks are

Which of the following amino acids has more than one carboxyl group?

Which amino acid possesses a guanidinium group in the side chain?

Which one of the following is a characteristic of the amino acid composition of a protein having an isoelectric pH (pI) of 4?

Gly-Gln-Ser-Lys-Met-Thr-Asp-Asn-Tyr What is the net charge of this peptide at pH 7.0?

From the following list select an amino acid with a side chain having strong UV-absorbing power

To which amino acid does cysteine have the closest chemical resemblance?

Characteristics of disulfide bonds in proteins include all of the following EXCEPT

Which of the following secondary structures is not commonly seen in proteins?

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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