Question 1

The amino acid threonine, (2S,3R)-2-amino-3-hydroxybutanoic acid,has two chiral
centers.Draw a Fisher projection of threonine.

Accepted Answer

The answer of The amino acid threonine, (2S,3R)-2-amino-3-hydroxybutanoic acid,has two...

Question 2

Pipecolic acid logically would be substituted for which natural amino acid in the synthesis of peptide analogs?

Accepted Answer

A)  Histidine 
B)  Proline 
C)  Tryptophan 
D)  Phenylalanine 
E)  Tyrosine 
A)  Histidine 
B)  Proline 
C)  Tryptophan 
D)  Phenylalanine 
E)  Tyrosine

Question 3

The study of all proteins that are expressed in a cell at a given time is called ___________.

Accepted Answer

The answer of The study of all proteins that are...

Question 4

All reactions that occur in living cells are mediated by biological catalysts called ___________.The prevailing hypothesis for enzyme catalysis is called the ____________ hypothesis.

Accepted Answer

enzymes;lo

Question 5

For the accompanying fully-protonated amino acid,what is the arrangement of pKa values in order of increasing magnitude?

Accepted Answer

A)  I < II < III 
B)  II < I < III 
C)  III < I < II 
D)  III < II < I 
E)  II < III < I 
A)  I < II < III 
B)  II < I < III 
C)  III < I < II 
D)  III < II < I 
E)  II < III < I

Question 6

Peptide synthesis has four basic steps.These are:

Accepted Answer

protect the N-terminus,activat

Question 7

Draw the structure of the following tripeptide (starting with the N-terminal residue and ending with the C-terminal residue),showing stereochemical details:
Val-Trp-Asn

Accepted Answer

The answer of Draw the structure of the following tripeptide...

Question 8

When the pentapeptide below is heated first with 2,4-dinitrofluorobenzene (and base)and then subjected to acidic hydrolysis,which amino acid will bear the dinitrophenyl group? Leu·Val·Gly·Phe·Ile

Accepted Answer

A)  Leucine 
B)  Valine 
C)  Glycine 
D)  Phenylalanine 
E)  Isoleucine 
A)  Leucine 
B)  Valine 
C)  Glycine 
D)  Phenylalanine 
E)  Isoleucine

Question 9

The Henderson-Hasselbach equation shows that the ________________ of an acid is the ________________ at which the acid is half-neutralized.

Accepted Answer

The answer of The Henderson-Hasselbach equation shows that the ________________...

Question 10

Using the three-letter code names for amino acids,write the structures of all possible peptides containing these amino acids: Val,Ser,Leu

Accepted Answer

Val-Leu-Ser Ser-Val-

Question 11

Complete the following equations:

Accepted Answer

The answer of Complete the following equations:  ...

Question 12

Which of these natural amino acids contains an imidazole ring?

Accepted Answer

A)  Histidine 
B)  Lysine 
C)  Tryptophan 
D)  4-Hydroxyproline 
E)  Two of the above 
A)  Histidine 
B)  Lysine 
C)  Tryptophan 
D)  4-Hydroxyproline 
E)  Two of the above

Question 13

The most widely used method for identifying the N-terminal amino acid in a peptide chain is called the ____________.

Accepted Answer

The answer of The most widely used method for identifying...

Question 14

Which of these amino acids cannot be described as an L amino acid?

Accepted Answer

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

Question 15

Show the structures of the products obtained on reaction of valine with ninhydrin.

Accepted Answer

The answer of Show the structures of the products obtained...

Question 16

Which one of these amino acids does not give the usual purple color with ninhydrin?

Accepted Answer

A)  Histidine 
B)  Proline 
C)  Tryptophan 
D)  Leucine 
E)  Aspartic acid 
A)  Histidine 
B)  Proline 
C)  Tryptophan 
D)  Leucine 
E)  Aspartic acid

Question 17

Beginning with a three-carbon alcohol,outline all necessary steps in the preparation of D,L-alanine.

Accepted Answer

The answer of Beginning with a three-carbon alcohol,outline all necessary...

Question 18

Which of these natural amino acids contains a pyrrolidine ring?

Accepted Answer

A)  Phenylalanine 
B)  Tyrosine 
C)  Tryptophan 
D)  4-Hydroxyproline 
E)  Serine 
A)  Phenylalanine 
B)  Tyrosine 
C)  Tryptophan 
D)  4-Hydroxyproline 
E)  Serine

Question 19

Predict the direction of migration (toward anode or cathode)of alanine during electrophoresis at pH = 5.

Accepted Answer

The pH = 5 is lower than pI =

Question 20

The secondary structure of proteins is derived from:

Accepted Answer

A)  peptide linkages. 
B)  disulfide linkages. 
C)  hydrogen bond formation. 
D)  hydrophobic interactions. 
E)  acid-base interactions. 
A)  peptide linkages. 
B)  disulfide linkages. 
C)  hydrogen bond formation. 
D)  hydrophobic interactions. 
E)  acid-base interactions.

Exam 24: Amino Acids and Proteins

The amino acid threonine, (2S,3R)-2-amino-3-hydroxybutanoic acid,has two chiral centers.Draw a Fisher projection of threonine.

Pipecolic acid logically would be substituted for which natural amino acid in the synthesis of peptide analogs?

The study of all proteins that are expressed in a cell at a given time is called ___________.

All reactions that occur in living cells are mediated by biological catalysts called ___________.The prevailing hypothesis for enzyme catalysis is called the ____________ hypothesis.

For the accompanying fully-protonated amino acid,what is the arrangement of pKa values in order of increasing magnitude?

Peptide synthesis has four basic steps.These are:

Draw the structure of the following tripeptide (starting with the N-terminal residue and ending with the C-terminal residue),showing stereochemical details: Val-Trp-Asn

When the pentapeptide below is heated first with 2,4-dinitrofluorobenzene (and base)and then subjected to acidic hydrolysis,which amino acid will bear the dinitrophenyl group? Leu·Val·Gly·Phe·Ile

The Henderson-Hasselbach equation shows that the ________________ of an acid is the ________________ at which the acid is half-neutralized.

Using the three-letter code names for amino acids,write the structures of all possible peptides containing these amino acids: Val,Ser,Leu

Complete the following equations:

Which of these natural amino acids contains an imidazole ring?

The most widely used method for identifying the N-terminal amino acid in a peptide chain is called the ____________.

Which of these amino acids cannot be described as an L amino acid?

Show the structures of the products obtained on reaction of valine with ninhydrin.

Which one of these amino acids does not give the usual purple color with ninhydrin?

Beginning with a three-carbon alcohol,outline all necessary steps in the preparation of D,L-alanine.

Which of these natural amino acids contains a pyrrolidine ring?

Predict the direction of migration (toward anode or cathode)of alanine during electrophoresis at pH = 5.

The secondary structure of proteins is derived from:

Carbon Compounds and Chemical Bonds

Representative Carbon Compounds: Functional Groups, Intermolecular Forces, and Infrared Ir Spectroscopy

An Introduction to Organic Reactions: Acids and Bases

Alkanes: Nomenclature, Conformational Analysis, and an Introduction to Synthesis

Stereochemistry: Chiral Molecules

Ionic Reactions - Nucleophilic Substitution and Elimination Reactions of Alkyl Halides

Alkenes and Alkynes I: Properties and Synthesis, Elimination Reactions of Alkyl Halides

Alkenes and Alkynes Ii: Addition Reactions

Nuclear Magnetic Resonance and Mass Spectrometry: Tools for Structure Determination

Radical Reactions

Alcohols and Ethers

Alcohols From Carbonyl Compounds Oxidation-Reduction and Organometallic Compounds

Conjugated Unsaturated Systems

Aromatic Compounds

Reactions of Aromatic Compounds

Aldehydes and Ketones I Nucleophilic Addition to the Carbonyl Group

Aldehydes and Ketones Ii Aldol Reactions

Carboxylic Acids and Their Derivatives Nucleophilic Addition - Elimination at the Acyl Carbon

Synthesis and Reactions of Beta-Dicarbonyl Compounds: More Chemistry of Enolate Ions

Amines

Phenols and Aryl Halides: Nucleophilic Aromatic Substitution

Carbohydrates

Lipids

Nucleic Acids and Protein Synthesis

Filters

All reactions that occur in living cells are mediated by biological catalysts called _.The prevailing hypothesis for enzyme catalysis is called the __ hypothesis.

For the accompanying fully-protonated amino acid,what is the arrangement of pK_a values in order of increasing magnitude?

The Henderson-Hasselbach equation shows that the of an acid is the at which the acid is half-neutralized.