Question 1

If a cis peptide bond is found in a protein, the most likely amino acid to contribute the amine to the amide bond is ______.

Accepted Answer

A) phenylalanine 
B) leucine 
C) proline 
D) glycine 
E) arginine 
A) phenylalanine 
B) leucine 
C) proline 
D) glycine 
E) arginine C

Question 2

Which of the following bonds has partial double bond character?

Accepted Answer

A) 1 
B) 2 
C) 3 
D) 4 
E) 5 
A) 1 
B) 2 
C) 3 
D) 4 
E) 5 C

Question 3

Draw each of the structures of aspartic acid that predominate at pH 1, 3, 7, and 11.

Accepted Answer

1 3 7 11

Question 4

Which of the following pairs of amino acids could form a charge-charge interaction through their R-groups?

Accepted Answer

A) methionine and histidine 
B) glutamine and lysine 
C) serine and glutamic acid 
D) aspartic acid and arginine 
E) threonine and asparagine 
A) methionine and histidine 
B) glutamine and lysine 
C) serine and glutamic acid 
D) aspartic acid and arginine 
E) threonine and asparagine

Question 5

Hydrolysis of a peptide bond produces:

Accepted Answer

A) an alcohol and an amine 
B) an amine and a carboxylic acid 
C) a carboxylic acid and an anhydride 
D) an amide and a carboxylic acid 
E) an alcohol and an amide 
A) an alcohol and an amine 
B) an amine and a carboxylic acid 
C) a carboxylic acid and an anhydride 
D) an amide and a carboxylic acid 
E) an alcohol and an amide

Question 6

Which of the following pairs of amino acids represents a conservation of the type of amino acid when considering the sequence of a protein from different species?

Accepted Answer

A) Asp and Asn 
B) Lys and His 
C) Leu and Val 
D) Gly and Ile 
E) Phe and Trp 
A) Asp and Asn 
B) Lys and His 
C) Leu and Val 
D) Gly and Ile 
E) Phe and Trp

Question 7

Which of the following amino acids is derived from another amino acid by the addition of an amine group?

Accepted Answer

A) lysine 
B) asparagine 
C) arginine 
D) histidine 
E) none of the above 
A) lysine 
B) asparagine 
C) arginine 
D) histidine 
E) none of the above

Question 8

Which of the following events occurs after the formation of disulfide bonds during the conversion of preproinsulin to mature insulin?

Accepted Answer

A) folding of proinsulin into a stable conformation 
B) transport of the molecule through the membranes 
C) cleavage of the peptide sequence that joins the A and B chains 
D) cleavage of the leader sequence 
E) posttranslational modification of specific proline residues 
A) folding of proinsulin into a stable conformation 
B) transport of the molecule through the membranes 
C) cleavage of the peptide sequence that joins the A and B chains 
D) cleavage of the leader sequence 
E) posttranslational modification of specific proline residues

Question 9

At a pH of 5, all amino acids have at least ____ charged group(s)and at most, _____ charged group(s).

Accepted Answer

A) 0; 1 
B) 1; 1 
C) 1; 2 
D) 2; 2 
E) 2; 3 
A) 0; 1 
B) 1; 1 
C) 1; 2 
D) 2; 2 
E) 2; 3

Question 10

Of the following amino acids, which will have a pI closest to 3?

Accepted Answer

A) Cys 
B) His 
C) Gly 
D) Asp 
E) Lys 
A) Cys 
B) His 
C) Gly 
D) Asp 
E) Lys

Question 11

Given the following peptide, what pair of protease enzymes would be able to produce three smaller peptides? Gly-Ser-Ala-His-Phe-Pro-Asn-Ala-Val-Glu-Cys-Ala-Ser

Accepted Answer

A) chymotrypsin and thrombin 
B) trypsin and chymotrypsin 
C) thermolysin and chymotrypsin 
D) trypsin and thermolysin 
E) none of the above 
A) chymotrypsin and thrombin 
B) trypsin and chymotrypsin 
C) thermolysin and chymotrypsin 
D) trypsin and thermolysin 
E) none of the above

Question 12

The conversion of ________ represents a conservative change while the conversion of ________ represents a nonconservative change.

Accepted Answer

A) Asp to Arg; Ile to Ser 
B) Tyr to Phe; Lys to Arg 
C) Gln to Asn; Ser to Thr 
D) Ile to Leu; Asn to Ala 
E) Cys to His; Lys to Glu 
A) Asp to Arg; Ile to Ser 
B) Tyr to Phe; Lys to Arg 
C) Gln to Asn; Ser to Thr 
D) Ile to Leu; Asn to Ala 
E) Cys to His; Lys to Glu

Question 13

What is the sequence of the following peptide?

Accepted Answer

A) Ile-Ala-Glu 
B) Val-Ala-Asp 
C) Leu-Gly-Glu 
D) Val-Ala-Asn 
E) Val-Gly-Gln 
A) Ile-Ala-Glu 
B) Val-Ala-Asp 
C) Leu-Gly-Glu 
D) Val-Ala-Asn 
E) Val-Gly-Gln

Question 14

Which of the following is true regarding the $\alpha$-carbon of an amino acid?

Accepted Answer

A) there are always four different functional groups attached 
B) the most commonly occurring form of amino acids are the D-amino acids 
C) when assigning the R-S stereochemistry, the carboxylic acid is always the highest priority functional group 
D) for all amino acids except glycine, the $\alpha$-carbon is a stereocenter 
E) none of the above 
A) there are always four different functional groups attached 
B) the most commonly occurring form of amino acids are the D-amino acids 
C) when assigning the R-S stereochemistry, the carboxylic acid is always the highest priority functional group 
D) for all amino acids except glycine, the $\alpha$-carbon is a stereocenter 
E) none of the above

Question 15

A peptide was treated with protease enzymes and cyanogen bromide followed by complete hydrolysis of the resulting products. Based upon the following data, determine the sequence of the original peptide.
Chymotrypsin gave two peptides containing the following amino acids:
Leu, Pro
Asp, Gln, Arg, Met, Tyr, Val
Cyanogen bromide gave two peptides containing the following amino acids:
Asp, Met
Gln, Leu, Arg, Tyr, Pro, Val
Trypsin gave two peptides containing the following amino acids:
Gln, Leu, Tyr, Pro
Asp, Arg, Met, Val

Accepted Answer

Chymotrypsin treatment shows the C-term

Question 16

Which of the following undergoes an oxidation reaction to form a disulfide bond?

Accepted Answer

A) serine 
B) cysteine 
C) methionine 
D) threonine 
E) tyrosine 
A) serine 
B) cysteine 
C) methionine 
D) threonine 
E) tyrosine

Question 17

Which of the following pairs of amino acids could form a hydrogen bond through their R-groups?

Accepted Answer

A) serine and phenylalanine 
B) aspartic acid and methionine 
C) histidine and tyrosine 
D) alanine and glutamine 
E) leucine and cysteine 
A) serine and phenylalanine 
B) aspartic acid and methionine 
C) histidine and tyrosine 
D) alanine and glutamine 
E) leucine and cysteine

Question 18

The prevalence of the trans orientation in peptide bonds results in the R-groups of adjacent amino acids being oriented approximately ______ degrees with respect to each other.

Accepted Answer

A) 30 
B) 60 
C) 90 
D) 120 
E) 180 
A) 30 
B) 60 
C) 90 
D) 120 
E) 180

Question 19

Which of the following amino acids is incorporated into proteins during ribosomal protein synthesis?

Accepted Answer

A) sarcosine 
B) ornithine 
C) 4-hydroxyproline 
D) phosphoserine 
E) selenocysteine 
A) sarcosine 
B) ornithine 
C) 4-hydroxyproline 
D) phosphoserine 
E) selenocysteine

Question 20

The peptide hormone insulin is composed of two peptide held together primarily by what mechanism?

Accepted Answer

A) disulfide bonds between cysteine residues 
B) charge-charge interactions between acidic and basic amino acids 
C) extensive hydrogen bonding due to the relatively high serine and glutamine content 
D) hydrophobic interactions 
E) an amide bond formed from the R-groups of a glutamic acid residue and a lysine residue 
A) disulfide bonds between cysteine residues 
B) charge-charge interactions between acidic and basic amino acids 
C) extensive hydrogen bonding due to the relatively high serine and glutamine content 
D) hydrophobic interactions 
E) an amide bond formed from the R-groups of a glutamic acid residue and a lysine residue

Exam 5: Introduction to Proteins: the Primary Level of Protein Structure

If a cis peptide bond is found in a protein, the most likely amino acid to contribute the amine to the amide bond is ______.

Which of the following bonds has partial double bond character?

Draw each of the structures of aspartic acid that predominate at pH 1, 3, 7, and 11.

Which of the following pairs of amino acids could form a charge-charge interaction through their R-groups?

Hydrolysis of a peptide bond produces:

Which of the following pairs of amino acids represents a conservation of the type of amino acid when considering the sequence of a protein from different species?

Which of the following amino acids is derived from another amino acid by the addition of an amine group?

Which of the following events occurs after the formation of disulfide bonds during the conversion of preproinsulin to mature insulin?

At a pH of 5, all amino acids have at least ____ charged group(s)and at most, _____ charged group(s).

Of the following amino acids, which will have a pI closest to 3?

Given the following peptide, what pair of protease enzymes would be able to produce three smaller peptides? Gly-Ser-Ala-His-Phe-Pro-Asn-Ala-Val-Glu-Cys-Ala-Ser

The conversion of ________ represents a conservative change while the conversion of ________ represents a nonconservative change.

What is the sequence of the following peptide?

Which of the following is true regarding the α\alphaα -carbon of an amino acid?

Which of the following undergoes an oxidation reaction to form a disulfide bond?

Which of the following pairs of amino acids could form a hydrogen bond through their R-groups?

The prevalence of the trans orientation in peptide bonds results in the R-groups of adjacent amino acids being oriented approximately ______ degrees with respect to each other.

Which of the following amino acids is incorporated into proteins during ribosomal protein synthesis?

The peptide hormone insulin is composed of two peptide held together primarily by what mechanism?

The Scope of Biochemistry

The Matrix of Life: Weak Interactions in an Aqueous Environment

The Energetics of Life

Nucleic Acids

The Three-Dimensional Structure of Proteins

Protein Function and Evolution

Contractile Proteins and Molecular Motors

Carbohydrates: Sugars, Saccharides, Glycans

Lipids, Membranes and Cellular Transport

Enzymes: Biological Catalysts

Chemical Logic of Metabolism

Carbohydrate Metabolism: Glycolysis, Gluconeogenesis, Glycogen Metabolism, and the Pentose Phosphate Pathway

Citric Acid Cycle and Glyoxylate Cycle

Electron Transport, Oxidative Phosphorylation, and Oxygen Metabolism

Photosynthesis

Lipid Metabolism I: Fatty Acids, Triacylglycerols, and Lipoproteins

Interorgan and Intracellular Coordination of Energy Metabolism in Vertebrates

Lipid Metabolism Ii: Membrane Lipids, Steroids, Isoprenoids, and Eicosanoids

Metabolism of Nitrogenous Compounds I: Principles of Biosynthesis, Utilization, and Turnover

Metabolism of Nitogenous Compounds II: Amino Acids, Porphyrins, and Neurotransmitters

Nucleotide Metabolism

Mechanisms of Signal Transduction

Genes, Genomes and Chromosomes

DNA Replication

DNA Restructuring: Repair, Recombination, Rearrangement, Amplification

Information Readout: Transcription and Post-Transcriptional Processing

Information Decoding: Translation and Post-Translational Protein Processing

Regulation of Gene Expression

Filters

At a pH of 5, all amino acids have at least charged group(s)and at most, _ charged group(s).

The conversion of represents a conservative change while the conversion of represents a nonconservative change.

Which of the following is true regarding the $\alpha$ -carbon of an amino acid?