Question 1

A "conjugated protein" is one which:

Accepted Answer

A)  possesses catalytic properties. 
B)  is a digestive enzyme. 
C)  exists largely as an α-helix. 
D)  contains unsaturated amino acids. 
E)  contains a nonprotein group as part of the molecule. 
A)  possesses catalytic properties. 
B)  is a digestive enzyme. 
C)  exists largely as an α-helix. 
D)  contains unsaturated amino acids. 
E)  contains a nonprotein group as part of the molecule. E

Question 2

Which of these natural amino acids,when present in a polypeptide,is not likely to exhibit significant hydrogen bonding through its side chain?

Accepted Answer

A)  Leucine 
B)  Threonine 
C)  Tyrosine 
D)  Serine 
E)  All of these are likely to exhibit significant hydrogen bonding through the side chain 
A)  Leucine 
B)  Threonine 
C)  Tyrosine 
D)  Serine 
E)  All of these are likely to exhibit significant hydrogen bonding through the side chain A

Question 3

One common method of analysis used to measure the approximate molecular weight of a protein is called _____________.

Accepted Answer

gel electrophoresis

Question 4

The pH at which the concentration of the dipolar ion (zwitterion)form of an amino acid is at a maximum and the cationic and anionic forms are at equal concentrations is termed the

Accepted Answer

A)  end point. 
B)  equivalence point. 
C)  neutral point. 
D)  isoelectric point. 
E)  dipolar point. 
A)  end point. 
B)  equivalence point. 
C)  neutral point. 
D)  isoelectric point. 
E)  dipolar point.

Question 5

Draw the Fisher projection of a threonine diastereomer,and label the chiral centers as R
or S.

Accepted Answer

The answer of Draw the Fisher projection of a threonine...

Question 6

Which amino acid is unlikely to be found in a natural protein?

Accepted Answer

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

Question 7

Amino acids can be prepared from aldehydes by treatment with ammonia and HCN followed by hydrolysis.This method is known as the ___________.

Accepted Answer

The answer of Amino acids can be prepared from aldehydes...

Question 8

The folding of the polyamide chain gives rise to higher levels of complexity called the _______________ and ______________ of the protein.

Accepted Answer

secondary;

Question 9

The Edman degradation uses this reagent to identify the N-terminal amino acid of a peptide or protein.

Accepted Answer

A)  C6H5NHNH2 
B)  C6H5NH2 
C)  C6H5N=C=S 
D)  C6H5N=C=O 
E)  Aminopeptidase 
A)  C6H5NHNH2 
B)  C6H5NH2 
C)  C6H5N=C=S 
D)  C6H5N=C=O 
E)  Aminopeptidase

Question 10

Which of these natural amino acids contains a heterocyclic ring?

Accepted Answer

A)  Asparagine 
B)  Proline 
C)  Arginine 
D)  Histidine 
E)  B and D 
A)  Asparagine 
B)  Proline 
C)  Arginine 
D)  Histidine 
E)  B and D

Question 11

How many different tripeptides can exist,each containing one residue of glycine,one of L-threonine,and one of L-arginine?

Accepted Answer

A)  2 
B)  3 
C)  6 
D)  8 
E)  9 
A)  2 
B)  3 
C)  6 
D)  8 
E)  9

Question 12

Which of these amino acids is an R amino acid?

Accepted Answer

A)  II and IV 
B)  IV and V 
C)  I and III 
D)  V 
E)  All of these are R amino acids 
A)  II and IV 
B)  IV and V 
C)  I and III 
D)  V 
E)  All of these are R amino acids

Question 13

Draw the structure of the following tripeptide (starting with the N-terminal residue and ending with the C-terminal residue),showing stereochemical details:
Ala-Ser-Leu

Accepted Answer

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

Question 14

What is the pI of the following amino acid?

Accepted Answer

A)  12 
B)  3.6 
C)  4.8 
D)  6.0 
E)  7.2 
A)  12 
B)  3.6 
C)  4.8 
D)  6.0 
E)  7.2

Question 15

Show how a Strecker synthesis might be used to prepare phenylalanine starting from phenylacetldehyde.

Accepted Answer

The answer of Show how a Strecker synthesis might be...

Question 16

Which of these amino acids is described as an "essential" amino acid?

Accepted Answer

A)  Methionine 
B)  Phenylalanine 
C)  Isoleucine 
D)  Tryptophan 
E)  All of these are "essential" amino acids 
A)  Methionine 
B)  Phenylalanine 
C)  Isoleucine 
D)  Tryptophan 
E)  All of these are "essential" amino acids

Question 17

What might be concluded upon determining that an unknown amino acid has its isoelectric point near pH 3?

Accepted Answer

A)  It must have a hydrophobic side chain 
B)  It must have a hydrophilic side chain 
C)  Its side chain must contain a basic group 
D)  Its side chain must contain more acidic groups then basic groups 
E)  None of the above is a valid conclusion 
A)  It must have a hydrophobic side chain 
B)  It must have a hydrophilic side chain 
C)  Its side chain must contain a basic group 
D)  Its side chain must contain more acidic groups then basic groups 
E)  None of the above is a valid conclusion

Question 18

Which amino acid would have its isoelectric point near pH 10?

Accepted Answer

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

Question 19

Complete the reaction presented below:

Accepted Answer

The answer of Complete the reaction presented below:  ...

Question 20

Which of these amino acids has the R configuration at the stereogenic center but,nonetheless,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

Exam 24: Amino Acids and Proteins

A "conjugated protein" is one which:

Which of these natural amino acids,when present in a polypeptide,is not likely to exhibit significant hydrogen bonding through its side chain?

One common method of analysis used to measure the approximate molecular weight of a protein is called _____________.

The pH at which the concentration of the dipolar ion (zwitterion)form of an amino acid is at a maximum and the cationic and anionic forms are at equal concentrations is termed the

Draw the Fisher projection of a threonine diastereomer,and label the chiral centers as R or S.

Which amino acid is unlikely to be found in a natural protein?

Amino acids can be prepared from aldehydes by treatment with ammonia and HCN followed by hydrolysis.This method is known as the ___________.

The folding of the polyamide chain gives rise to higher levels of complexity called the _______________ and ______________ of the protein.

The Edman degradation uses this reagent to identify the N-terminal amino acid of a peptide or protein.

Which of these natural amino acids contains a heterocyclic ring?

How many different tripeptides can exist,each containing one residue of glycine,one of L-threonine,and one of L-arginine?

Which of these amino acids is an R amino acid?

Draw the structure of the following tripeptide (starting with the N-terminal residue and ending with the C-terminal residue),showing stereochemical details: Ala-Ser-Leu

What is the pI of the following amino acid?

Show how a Strecker synthesis might be used to prepare phenylalanine starting from phenylacetldehyde.

Which of these amino acids is described as an "essential" amino acid?

What might be concluded upon determining that an unknown amino acid has its isoelectric point near pH 3?

Which amino acid would have its isoelectric point near pH 10?

Complete the reaction presented below:

Which of these amino acids has the R configuration at the stereogenic center but,nonetheless,is an L amino acid?

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

The folding of the polyamide chain gives rise to higher levels of complexity called the _ and of the protein.