Question 1

What is the product of the following reaction? (Assume workup to neutralize.)

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
A) I 
B) II 
C) III 
D) IV

Question 2

What is formed by the combination of four amino acids?

Accepted Answer

A) A protein 
B) A polypeptide 
C) A tripeptide 
D) A tetrapeptide 
A) A protein 
B) A polypeptide 
C) A tripeptide 
D) A tetrapeptide

Question 3

Which of the following amino acids is achiral?

Accepted Answer

A) Phenylalanine 
B) Glycine 
C) Valine 
D) Alanine 
A) Phenylalanine 
B) Glycine 
C) Valine 
D) Alanine

Question 4

Which is the correct structure for the amino acid cysteine?

Accepted Answer

A) A 
B) B 
C) C 
D) D 
A) A 
B) B 
C) C 
D) D

Question 5

Why can glycine not be resolved into two enantiomers?

Accepted Answer

A) It has no stereogenic centers. 
B) It has no nitrogen atoms. 
C) It has no aromatic rings. 
D) It cannot be converted into a salt. 
A) It has no stereogenic centers. 
B) It has no nitrogen atoms. 
C) It has no aromatic rings. 
D) It cannot be converted into a salt.

Question 6

What amino acid is at the C-terminus of the following peptide?

Accepted Answer

A) Valine 
B) Serine 
C) Alanine 
D) Proline 
A) Valine 
B) Serine 
C) Alanine 
D) Proline

Question 7

What is (are)the missing reagent(s)in the reaction below?

Accepted Answer

A) NH3 
B) HCN 
C) NaCN,NH4Cl 
D) NaNH2 
A) NH3 
B) HCN 
C) NaCN,NH4Cl 
D) NaNH2

Question 8

What is the configuration of naturally occurring amino acids?

Accepted Answer

A) D 
B) S 
C) L 
D) R 
A) D 
B) S 
C) L 
D) R

Question 9

Which of the following is the correct structure for aspartic acid at pH = 1?

Accepted Answer

A) A 
B) B 
C) C 
D) D 
A) A 
B) B 
C) C 
D) D

Question 10

Which of the following correctly describes the tertiary structure of a peptide?

Accepted Answer

A) the three-dimensional conformations of localized regions of a protein 
B) the particular sequence of amino acids that are joined together by peptide bonds 
C) the structure is defined by the b-pleated sheet form 
D) the three-dimensional shape adopted by the entire peptide 
A) the three-dimensional conformations of localized regions of a protein 
B) the particular sequence of amino acids that are joined together by peptide bonds 
C) the structure is defined by the b-pleated sheet form 
D) the three-dimensional shape adopted by the entire peptide

Question 11

Which of the following is (are)fibrous protein(s)?

Accepted Answer

A) Keratins 
B) Hormones 
C) Enzymes 
D) Antibodies 
A) Keratins 
B) Hormones 
C) Enzymes 
D) Antibodies

Question 12

Which of the following correctly describes a peptide bond?

Accepted Answer

A) a bond between sp3-hybridized atoms only 
B) a bond usually found in the s-cis conformation 
C) an amide bond 
D) the result of the formation of the carbonyl group of one amino acid with a R-group from the other amino acid 
A) a bond between sp3-hybridized atoms only 
B) a bond usually found in the s-cis conformation 
C) an amide bond 
D) the result of the formation of the carbonyl group of one amino acid with a R-group from the other amino acid

Question 13

Which of the following is the major advantage of the Merrifield synthesis of peptides?

Accepted Answer

A) It allows for the formation of absolutely no by-products. 
B) Impurities can be easily washed away. 
C) Excess reagent can be used. 
D) It prevents hydrogenation. 
A) It allows for the formation of absolutely no by-products. 
B) Impurities can be easily washed away. 
C) Excess reagent can be used. 
D) It prevents hydrogenation.

Question 14

What is the IUPAC or common name for the following compound?

Accepted Answer

A) Cysteinylalanine 
B) Alanylcysteine 
C) Serinylalanine 
D) Alanylserine 
A) Cysteinylalanine 
B) Alanylcysteine 
C) Serinylalanine 
D) Alanylserine

Question 15

Give the order (1st to last)in which the following amino acids would be eluted with a buffer of pH = 4 from a column containing a cationic-exchange resin (Dowex 50): Arg (pI = 10.8),Ser (pI = 5.7),Asp (pI = 2.8)and His (pI = 7.6).

Accepted Answer

A) His,Ser,Asp,Arg 
B) Arg,His,Ser,Asp 
C) His,Ser,Arg,Asp 
D) Asp,Ser,His,Arg 
A) His,Ser,Asp,Arg 
B) Arg,His,Ser,Asp 
C) His,Ser,Arg,Asp 
D) Asp,Ser,His,Arg

Question 16

Which of the following compounds is not an amino acid?

Accepted Answer

A) A 
B) B 
C) C 
D) D 
A) A 
B) B 
C) C 
D) D

Question 17

What are the only covalent bonds that stabilize the tertiary structure of a peptide?

Accepted Answer

A) Hydrogen bonds 
B) Disulfide bonds 
C) Van der Waal bonds 
D) Ionic bonds 
A) Hydrogen bonds 
B) Disulfide bonds 
C) Van der Waal bonds 
D) Ionic bonds

Question 18

Which of the following correctly describes the Merrifield synthesis?

Accepted Answer

A) It uses a solid phase technique for the synthesis of peptides. 
B) It uses DCC (dicyclohexylcarbodiimide)to form the amide bond in a peptide synthesis. 
C) It uses BOC (tert-butoxycarbonyl)as a protecting group for peptide synthesis. 
D) It uses aqueous phase techniques for the synthesis of large polypeptides. 
A) It uses a solid phase technique for the synthesis of peptides. 
B) It uses DCC (dicyclohexylcarbodiimide)to form the amide bond in a peptide synthesis. 
C) It uses BOC (tert-butoxycarbonyl)as a protecting group for peptide synthesis. 
D) It uses aqueous phase techniques for the synthesis of large polypeptides.

Question 19

What is the product of the following reaction? (Assume workup to neutralize.)

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
A) I 
B) II 
C) III 
D) IV

Question 20

What is the product of the following reaction? (Assume workup to neutralize.)

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
A) I 
B) II 
C) III 
D) IV

Exam 27: Amino Acids and Proteins

What is the product of the following reaction? (Assume workup to neutralize.)

What is formed by the combination of four amino acids?

Which of the following amino acids is achiral?

Which is the correct structure for the amino acid cysteine?

Why can glycine not be resolved into two enantiomers?

What amino acid is at the C-terminus of the following peptide?

What is (are)the missing reagent(s)in the reaction below?

What is the configuration of naturally occurring amino acids?

Which of the following is the correct structure for aspartic acid at pH = 1?

Which of the following correctly describes the tertiary structure of a peptide?

Which of the following is (are)fibrous protein(s)?

Which of the following correctly describes a peptide bond?

Which of the following is the major advantage of the Merrifield synthesis of peptides?

What is the IUPAC or common name for the following compound?

Give the order (1st to last)in which the following amino acids would be eluted with a buffer of pH = 4 from a column containing a cationic-exchange resin (Dowex 50): Arg (pI = 10.8),Ser (pI = 5.7),Asp (pI = 2.8)and His (pI = 7.6).

Which of the following compounds is not an amino acid?

What are the only covalent bonds that stabilize the tertiary structure of a peptide?

Which of the following correctly describes the Merrifield synthesis?

What is the product of the following reaction? (Assume workup to neutralize.)

What is the product of the following reaction? (Assume workup to neutralize.)

Structure and Bonding

Acids and Bases

Introduction to Organic Molecules and Functional Groups

Alkanes

Stereochemistry

Understanding Organic Reactions

Alkyl Halides and Nucleophilic Substitution

Alkyl Halides and Elimination Reactions

Alcohols,ethers,and Related Compounds

Alkenes and Addition Reactions

Alkynes and Synthesis

Oxidation and Reduction

Radical Reactions

Conjugation,resonance,and Dienes

Benzene and Aromatic Compounds

Reactions of Aromatic Compounds

Introduction to Carbonyl Chemistry; Organometallic Reagents; Oxidation and Reduction

Aldehydes and Ketones - Nucleophilic Addition

Carboxylic Acids and the Acidity of the O-H Bond

Carboxylic Acids and Their Derivatives Nucleophilic Acyl Substitution

Substitution Reactions of Carbonyl Compounds at the a Carbon

Carbonyl Condensation Reactions

Amines

Carbon-Carbon Bond-Forming Reactions in Organic Synthesis

Pericyclic Reactions

Carbohydrates

Synthetic Polymers

Lipids

Spectroscopy A: Mass Spectrometry

Spectroscopy B: Infrared Spectroscopy

Spectroscopy C: Nuclear Magnetic Resonance Spectroscopy

Filters

Give the order (1^st to last)in which the following amino acids would be eluted with a buffer of pH = 4 from a column containing a cationic-exchange resin (Dowex 50): Arg (pI = 10.8),Ser (pI = 5.7),Asp (pI = 2.8)and His (pI = 7.6).