Question 1

The artificial sweetener aspartame is a derivative of the dipeptide asp-phe.If aspartame (asp-phe) was prepared from racemic amino acids,how many stereoisomers (diastereomers + enantiomers) could be formed?

Accepted Answer

A)   2
B)   3
C)   4
D)   6
E)   8F) D) and E)
G) A) and B)

Question 2

Disulfide bonds in proteins

Accepted Answer

A)   result from oxidation of thiols (RSH) .
B)   function to help maintain the shape of proteins.
C)   can be broken by reduction reactions.
D)   link two cysteine amino acid residues.
E)   All of these are true.F) C) and D)
G) B) and C)

Question 3

Which of the following amino acids contains an aromatic ring?

Accepted Answer

A)   Alanine
B)   Serine
C)   Tyrosine
D)   Asparagine
E)   GlycineF) A) and B)
G) A) and C)

Question 4

Which amino acid is shown?

Accepted Answer

A)   Alanine
B)   Glycine
C)   Tyrosine
D)   Lysine
E)   ArginineF) None of the above
G) C) and E)

Question 5

The difference(s) between DNA and RNA is (are) :

Accepted Answer

A)   DNA incorporates 2-deoxyribose sugars rather than ribose.
B)   RNA is smaller than DNA.
C)   DNA uses thymine,RNA uses uracil.
D)   Two of the above are true.
E)   All of the above are true.F) B) and D)
G) C) and D)

Question 6

Which nitrogen in the imidazole ring of histidine is the more basic?

Accepted Answer

A)   #1
B)   #2
C)   both have same basicity
D)   neither is basic
E)   the histidine N-H is actually acidicF) A) and C)
G) A) and B)

Question 7

The primary structure of a protein refers to the

Accepted Answer

A)   sequence of amino acids.
B)   overall 3-dimensional shape.
C)   localized shape of the backbone.
D)   degree of aggregation with other proteins.
E)   structure of the active site.F) B) and E)
G) A) and B)

Question 8

Given that the pKa of the acidic form of proline is 2.0,and the pKa of the basic form of proline is 10.6,what is the isoelectric point?

Accepted Answer

A)   2.0
B)   6.3
C)   4.4
D)   10.6
E)   7.0F) B) and D)
G) All of the above

Question 9

In a DNA molecule,at which point would the base shown be attached to a deoxyribose fragment?

Accepted Answer

A)   1
B)   2
C)   3
D)   4
E)   5F) C) and D)
G) B) and E)

Question 10

What material can be used repetitively (on a given sample) to sequence a polypeptide from the N-terminal end?

Accepted Answer

A)   Chymotrypsin
B)   Sanger reagent
C)   Trypsin
D)   Edman reagent
E)   CarboxypeptidaseF) None of the above
G) A) and B)

Question 11

How many tripeptides containing one residue each of L-alanine,L-valine,and glycine are possible?

Accepted Answer

A)   2
B)   3
C)   4
D)   6
E)   9F) None of the above
G) C) and D)

Question 12

Which of the following amino acids would have the highest isoelectric point?

Accepted Answer

A)   Lysine
B)   Glutamine
C)   Aspartic acid
D)   Alanine
E)   TryptophanF) C) and D)
G) C) and E)

Question 13

How many amino acid residues are present in the following polypeptide?

Accepted Answer

A)   4
B)   5
C)   6
D)   7
E)   8F) B) and D)
G) A) and E)

Question 14

Which of the following statements is not true of amino acids?

Accepted Answer

A)   They are less acidic than carboxylic acids.
B)   In acid solution (pH ~ 2) they would show an IR absorption near 1720 cm-1.
C)   They are soluble in water but not in non-polar organic solvents.
D)   They are more basic than amines.
E)   In basic solution (pH ~ 12) they would show an IR absorption near 3300 cm-1.F) A) and C)
G) A) and E)

Question 15

How many polypeptides would be present if the following was treated with trypsin?

Accepted Answer

A)   1
B)   2
C)   3
D)   4
E)   5F) A) and E)
G) A) and D)

Question 16

Which of the following amino acids is theoretically capable of existing in two diastereomeric forms?

Accepted Answer

A)   Cysteine
B)   Threonine
C)   Leucine
D)   Serine
E)   TryptophanF) C) and D)
G) B) and C)

Question 17

At the isoelectric point,the amino acid alanine will exist as what structure?

Accepted Answer

A)   A positive ion
B)   A negative ion
C)   An uncharged molecule
D)   A zwitterion
E)   A carbocationF) C) and D)
G) All of the above

Question 18

The organic portion of which of the following biological materials does not consist mainly of polypeptides and/or proteins?

Accepted Answer

A)   Enzymes
B)   Hair
C)   Hemoglobin
D)   Membranes
E)   InsulinF) B) and C)
G) All of the above

Question 19

Which of the following DNA base pairs can participate in Watson and Crick type hydrogen bonding?

Accepted Answer

A)   A-T
B)   G-T
C)   G-C
D)   Both A and B
E)   Both A and CF) A) and E)
G) D) and E)

Exam 26: Amino Acids,peptides,proteins,and Nucleic Acids: Nitrogen-Containing Polymers in Nature

How many polypeptides would be present if the following was treated with trypsin?

Correct Answer
verified

The organic portion of which of the following biological materials does not consist mainly of polypeptides and/or proteins?

Correct Answer
verified

Which of the following amino acids is theoretically capable of existing in two diastereomeric forms?

Correct Answer
verified

Which of the following amino acids contains an aromatic ring?

Correct Answer
verified

Given that the pK_a of the acidic form of proline is 2.0,and the pK_a of the basic form of proline is 10.6,what is the isoelectric point?

Correct Answer
verified

In a DNA molecule,at which point would the base shown be attached to a deoxyribose fragment?

Correct Answer
verified

The artificial sweetener aspartame is a derivative of the dipeptide asp-phe.If aspartame (asp-phe) was prepared from racemic amino acids,how many stereoisomers (diastereomers + enantiomers) could be formed?

Correct Answer
verified

How many amino acid residues are present in the following polypeptide?

Correct Answer
verified

Which of the following DNA base pairs can participate in Watson and Crick type hydrogen bonding?

Correct Answer
verified

At the isoelectric point,the amino acid alanine will exist as what structure?

Correct Answer
verified

The difference(s) between DNA and RNA is (are) :

Correct Answer
verified

Disulfide bonds in proteins

Correct Answer
verified

How many tripeptides containing one residue each of L-alanine,L-valine,and glycine are possible?

Correct Answer
verified

The primary structure of a protein refers to the

Correct Answer
verified

Which of the following statements is not true of amino acids?

Correct Answer
verified

Which nitrogen in the imidazole ring of histidine is the more basic?

Correct Answer
verified

Which amino acid is shown?

Correct Answer
verified

What material can be used repetitively (on a given sample) to sequence a polypeptide from the N-terminal end?

Correct Answer
verified

Which of the following amino acids would have the highest isoelectric point?

Correct Answer
verified

Exam 26: Amino Acids,peptides,proteins,and Nucleic Acids: Nitrogen-Containing Polymers in Nature

How many polypeptides would be present if the following was treated with trypsin?

Correct AnswerverifiedShow Answer

The organic portion of which of the following biological materials does not consist mainly of polypeptides and/or proteins?

Correct AnswerverifiedShow Answer

Which of the following amino acids is theoretically capable of existing in two diastereomeric forms?

Correct AnswerverifiedShow Answer

Which of the following amino acids contains an aromatic ring?

Correct AnswerverifiedShow Answer

Given that the pKa of the acidic form of proline is 2.0,and the pKa of the basic form of proline is 10.6,what is the isoelectric point?

Correct AnswerverifiedShow Answer

In a DNA molecule,at which point would the base shown be attached to a deoxyribose fragment?

Correct AnswerverifiedShow Answer

The artificial sweetener aspartame is a derivative of the dipeptide asp-phe.If aspartame (asp-phe) was prepared from racemic amino acids,how many stereoisomers (diastereomers + enantiomers) could be formed?

Correct AnswerverifiedShow Answer

How many amino acid residues are present in the following polypeptide?

Correct AnswerverifiedShow Answer

Which of the following DNA base pairs can participate in Watson and Crick type hydrogen bonding?

Correct AnswerverifiedShow Answer

At the isoelectric point,the amino acid alanine will exist as what structure?

Correct AnswerverifiedShow Answer

The difference(s) between DNA and RNA is (are) :

Correct AnswerverifiedShow Answer

Disulfide bonds in proteins

Correct AnswerverifiedShow Answer

How many tripeptides containing one residue each of L-alanine,L-valine,and glycine are possible?

Correct AnswerverifiedShow Answer

The primary structure of a protein refers to the

Correct AnswerverifiedShow Answer

Which of the following statements is not true of amino acids?

Correct AnswerverifiedShow Answer

Which nitrogen in the imidazole ring of histidine is the more basic?

Correct AnswerverifiedShow Answer

Which amino acid is shown?

Correct AnswerverifiedShow Answer

What material can be used repetitively (on a given sample) to sequence a polypeptide from the N-terminal end?

Correct AnswerverifiedShow Answer

Which of the following amino acids would have the highest isoelectric point?

Correct AnswerverifiedShow Answer

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Given that the pK_a of the acidic form of proline is 2.0,and the pK_a of the basic form of proline is 10.6,what is the isoelectric point?

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