Question 1

Give the product for the following reaction.

Accepted Answer

A) alanine 
B) leucine 
C) valine 
D) isoleucine 
E) glycine 
A) alanine 
B) leucine 
C) valine 
D) isoleucine 
E) glycine

Question 2

Draw the form of L-lysine which is present at biological pH.

Accepted Answer

The answer of Draw the form of L-lysine which is...

Question 3

Which of the following is a zwitterion?

Accepted Answer

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

Question 4

The quaternary structure of proteins is concerned with which of the following?

Accepted Answer

A) sequence of amino acids in the peptide chain 
B) description of the way the peptide chains are arranged with respect to each other 
C) location of the disulfide bridges in the peptide chain 
D) conformation of the protein backbone 
E) three-dimensional arrangement of all atoms in the protein 
A) sequence of amino acids in the peptide chain 
B) description of the way the peptide chains are arranged with respect to each other 
C) location of the disulfide bridges in the peptide chain 
D) conformation of the protein backbone 
E) three-dimensional arrangement of all atoms in the protein

Question 5

Which of the following is an L-amino acid?

Accepted Answer

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

Question 6

Which of the following are capable of denaturing proteins?

Accepted Answer

A) organic solvents 
B) detergents 
C) extreme pH 
D) heat 
E) all of the above 
A) organic solvents 
B) detergents 
C) extreme pH 
D) heat 
E) all of the above

Question 7

Provide the structure of Ala-Ser-Gly at biological pH.

Accepted Answer

The answer of Provide the structure of Ala-Ser-Gly at biological...

Question 8

Draw structures for the forms of glycine present in basic, neutral, and acidic solutions.

Accepted Answer

+ + H₂N-CH₂-COO- H₃N-CH

Question 9

Identify the amino acid that is hydrolyzed by cyanogen bromide.

Accepted Answer

A) N-side of met 
B) C-side of gly 
C) C-side of met 
D) C-side of phe 
E) C-side of arg 
A) N-side of met 
B) C-side of gly 
C) C-side of met 
D) C-side of phe 
E) C-side of arg

Question 10

A decapeptide undergoes partial hydrolysis to give peptides whose amino acids are shown below. Reaction of the decapeptide with Edman's reagent releases PTH-leu. What is the sequence of the decapeptide? (1)Pro, Ser (5)Glu, Ser, Val, Pro
(2)Gly, Gly (6)Glu, Pro, Gly
(3)Met, Ala, Leu (7)Met, Leu
(4)Gly, Ala (8)His, Val

Accepted Answer

A) Leu-Met-Ala-Gly-Gly-Glu-Pro-Ser-His-Val 
B) Leu-Met-Ala-Gly-Gly-Glu-Ser-Pro-Val-His 
C) Leu-Ala-Met-Gly-Gly-Glu-Pro-Ser-Val-His 
D) Leu-Met-Gly-Ala-Gly-Glu-Pro-Ser-Val-His 
E) Leu-Met-Ala-Gly-Gly-Glu-Pro-Ser-Val-His 
A) Leu-Met-Ala-Gly-Gly-Glu-Pro-Ser-His-Val 
B) Leu-Met-Ala-Gly-Gly-Glu-Ser-Pro-Val-His 
C) Leu-Ala-Met-Gly-Gly-Glu-Pro-Ser-Val-His 
D) Leu-Met-Gly-Ala-Gly-Glu-Pro-Ser-Val-His 
E) Leu-Met-Ala-Gly-Gly-Glu-Pro-Ser-Val-His

Question 11

Name the following compound.

Accepted Answer

A) alanine 
B) leucine 
C) valine 
D) glycine 
E) isoleucine 
A) alanine 
B) leucine 
C) valine 
D) glycine 
E) isoleucine

Question 12

Draw a line where cleavage occurs with trypsin.

Accepted Answer

The answer of Draw a line where cleavage occurs with...

Question 13

Calculate the isoelectric point for the following compound.

Accepted Answer

A) 3)22 
B) 5)34 
C) 5)93 
D) 6)91 
E) 9)67 
A) 3)22 
B) 5)34 
C) 5)93 
D) 6)91 
E) 9)67

Question 14

What is the pI of glycine? The structure and pKa values are shown below.

Accepted Answer

A) 7)26 
B) 5)97 
C) 3)63 
D) 7)50 
E) 11.94 
A) 7)26 
B) 5)97 
C) 3)63 
D) 7)50 
E) 11.94

Question 15

Which of the following best describes the side chain of arginine at a pH of 11?

Accepted Answer

A) hydrophobic 
B) nonpolar 
C) charged and polar 
D) uncharged but polar 
E) aprotic 
A) hydrophobic 
B) nonpolar 
C) charged and polar 
D) uncharged but polar 
E) aprotic

Question 16

Phenyl isothiocyanate (PITC)is commonly known as Edman's reagent. Edman's reagent is widely used to identify which of the following?

Accepted Answer

A) the number and kind of amino acids in the protein 
B) the disulfide bridges in the protein 
C) C-terminal amino acid of the protein 
D) N-terminal amino acid of the protein 
E) the number of peptide bonds in the protein 
A) the number and kind of amino acids in the protein 
B) the disulfide bridges in the protein 
C) C-terminal amino acid of the protein 
D) N-terminal amino acid of the protein 
E) the number of peptide bonds in the protein

Question 17

In peptide synthesis, give the use of trifluoroacetic acid.

Accepted Answer

A) activates the carboxyl group of an amino acid 
B) protects the carboxyl group of an amino acid 
C) protects the amino group of an amino acid 
D) activates the amino group of an amino acid 
E) removes the protecting group on the N-terminal amino acid 
A) activates the carboxyl group of an amino acid 
B) protects the carboxyl group of an amino acid 
C) protects the amino group of an amino acid 
D) activates the amino group of an amino acid 
E) removes the protecting group on the N-terminal amino acid

Question 18

Rank the following amino acids in order of time of elution from a cation-exchange resin and a buffer pH of 4.0: aspartic acid, phenylalanine, arginine, and alanine.

Accepted Answer

aspartic acid > alan

Question 19

Which of the following amino acids has an aliphatic R group?

Accepted Answer

A) serine 
B) cysteine 
C) asparagine 
D) tyrosine 
E) leucine 
A) serine 
B) cysteine 
C) asparagine 
D) tyrosine 
E) leucine

Question 20

What is an amino acid analyzer?

Accepted Answer

An instrument that automates ion-exchang

Exam 22: Amino Acids, Peptides, and Proteins

Give the product for the following reaction.

Draw the form of L-lysine which is present at biological pH.

Which of the following is a zwitterion?

The quaternary structure of proteins is concerned with which of the following?

Which of the following is an L-amino acid?

Which of the following are capable of denaturing proteins?

Provide the structure of Ala-Ser-Gly at biological pH.

Draw structures for the forms of glycine present in basic, neutral, and acidic solutions.

Identify the amino acid that is hydrolyzed by cyanogen bromide.

Name the following compound.

Draw a line where cleavage occurs with trypsin.

Calculate the isoelectric point for the following compound.

What is the pI of glycine? The structure and pKa values are shown below.

Which of the following best describes the side chain of arginine at a pH of 11?

Phenyl isothiocyanate (PITC)is commonly known as Edman's reagent. Edman's reagent is widely used to identify which of the following?

In peptide synthesis, give the use of trifluoroacetic acid.

Rank the following amino acids in order of time of elution from a cation-exchange resin and a buffer pH of 4.0: aspartic acid, phenylalanine, arginine, and alanine.

Which of the following amino acids has an aliphatic R group?

What is an amino acid analyzer?

Remembering General Chemistry: Electronic Structure and Bonding

Acids and Bases: Central to Understanding Organic Chemistry

An Introduction to Organic Compounds

Isomers: the Arrangement of Atoms in Space

Alkenes Thermodynamics and Kinetics

Reactions of Alkenes

Reactions of Alkynes Introduction to Multistep Synthesis

Electron Delocalization, Resonance, and Aromaticity More About Molecular Orbital Theory

Substitution Reactions of Alkyl Halides

Elimination Reactions of Alkyl Halides Competition Between Substitution and Elimination

Reactions of Alcohols, Ethers, Epoxides, and Sulfur-Containing Compounds

Organometallic Compounds

Reactions of Alkanes, Radicals

Mass Spectrometry, Infrared Spectroscopy, and Uvvis Spectroscopy

Nmr Spectroscopy

Reactions of Carboxylic Acids and Carboxylic Acid Derivatives

Reactions of Aldehydes and Ketones

Reactions at the Alpha Carbon of Carbonyl Compounds

Reactions of Benzene and Substituted Benzenes

More About Amines Heterocylic Compounds

Carbohydrates

Catalysis

The Organic Mechanisms of the Coenzymes

The Chemistry of Metabolism

Nucleosides, Nucleotides, and Nucleic Acids

Synthetic Polymers

Pericyclic Reactions

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