Question 1

$\alpha$-Keratin found in nails has more strength than $\alpha$-keratin found in hair due to the presence of more ___________.

Accepted Answer

A)  hydrophobic interactions 
B)  salt bridges 
C)  ($\alpha$-helix) 
D)  disulfide bridges 
E)  pleated sheets 
A)  hydrophobic interactions 
B)  salt bridges 
C)  ($\alpha$-helix) 
D)  disulfide bridges 
E)  pleated sheets

Question 2

Which of the following is a correct structure for D-leucine?

Accepted Answer

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

Question 3

Provide the structure of the amino acid produced from the following reaction.

Accepted Answer

The answer of Provide the structure of the amino acid...

Question 4

Which of the following alkenes is used to prepare isoleucine using an asymmetric catalytic hydrogenation reaction?

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  IV 
E)  none of these 
A)  I 
B)  II 
C)  III 
D)  IV 
E)  none of these

Question 5

Which of the following amino acids will migrate towards the anode at pH 7?
Glycine: pI = 6.0
Lysine: pI = 9.7

Accepted Answer

The answer of Which of the following amino acids will...

Question 6

Which of the following results after three steps of Edman degradation of the heptapeptide Lys-His-Gly-Phe-Tyr-Ser-Ala?

Accepted Answer

A)  Lys-His-Gly 
B)  Phe-Tyr-Ser-Ala 
C)  Tyr-Ser-Ala 
D)  Lys-His-Gly-Phe 
E)  Gly-Phe-Tyr-Ser-Ala 
A)  Lys-His-Gly 
B)  Phe-Tyr-Ser-Ala 
C)  Tyr-Ser-Ala 
D)  Lys-His-Gly-Phe 
E)  Gly-Phe-Tyr-Ser-Ala

Question 7

Proteins that catalyze biochemical reactions are called ______.

Accepted Answer

A)  apoproteins 
B)  peptides 
C)  enzymes 
D)  transport proteins 
E)  cellular proteins 
A)  apoproteins 
B)  peptides 
C)  enzymes 
D)  transport proteins 
E)  cellular proteins

Question 8

How do enzymes speed up a reaction?

Accepted Answer

By lowerin

Question 9

Amino acids are considered amphoteric because _____________.

Accepted Answer

A)  they only react with acids 
B)  they only react with bases 
C)  they react with both acids and bases 
D)  they do not react with acids or bases 
E)  none of these 
A)  they only react with acids 
B)  they only react with bases 
C)  they react with both acids and bases 
D)  they do not react with acids or bases 
E)  none of these

Question 10

Draw the Fischer projection for L-aspartic acid and assign the configuration (R/S) at the chirality center.

Accepted Answer

The answer of Draw the Fischer projection for L-aspartic acid...

Question 11

Which amino acid is produced from the following reaction sequence?

Accepted Answer

A)  alanine 
B)  valine 
C)  leucine 
D)  isoleucine 
E)  none of these 
A)  alanine 
B)  valine 
C)  leucine 
D)  isoleucine 
E)  none of these

Question 12

Denaturation is ______.

Accepted Answer

A)  irreversible 
B)  reversible with heat 
C)  reversible with a catalyst 
D)  reversible with UV 
E)  reversible under the same conditions 
A)  irreversible 
B)  reversible with heat 
C)  reversible with a catalyst 
D)  reversible with UV 
E)  reversible under the same conditions

Question 13

Which of the following amino acids contain a polar side chain?

Accepted Answer

A)  tyrosine 
B)  proline 
C)  leucine 
D)  tryptophan 
E)  glycine 
A)  tyrosine 
B)  proline 
C)  leucine 
D)  tryptophan 
E)  glycine

Question 14

Which amino acid is produced from the following reaction sequence?

Accepted Answer

A)  alanine 
B)  valine 
C)  leucine 
D)  isoleucine 
E)  none of these 
A)  alanine 
B)  valine 
C)  leucine 
D)  isoleucine 
E)  none of these

Question 15

Which of the following is the correct sequence of the tetrapeptide that is formed by the following reaction sequence?

Accepted Answer

A)  Cys-Ala-Phe-Ser 
B)  Cys-Phe-Ala-Ser 
C)  Ser-Ala-Phe-Cys 
D)  Ser-Phe-Ala-Cys 
E)  none of these 
A)  Cys-Ala-Phe-Ser 
B)  Cys-Phe-Ala-Ser 
C)  Ser-Ala-Phe-Cys 
D)  Ser-Phe-Ala-Cys 
E)  none of these

Question 16

What is the correct sequence of amino acids for the following tripeptide?

Accepted Answer

A)  Leu-Phe-Ala 
B)  Val-Phe-Ala 
C)  Ile-Tyr-Leu 
D)  Leu-Tyr-Val 
E)  Val-Ala-Phe 
A)  Leu-Phe-Ala 
B)  Val-Phe-Ala 
C)  Ile-Tyr-Leu 
D)  Leu-Tyr-Val 
E)  Val-Ala-Phe

Question 17

Which of the following is a major component of the secondary structure of keratin found in hair?

Accepted Answer

A)  ($\beta$-pleated sheets) 
B)  ($\alpha$-pleated sheets) 
C)  ($\alpha$-helix) 
D)  ($\beta$-helix) 
E)  cylinder 
A)  ($\beta$-pleated sheets) 
B)  ($\alpha$-pleated sheets) 
C)  ($\alpha$-helix) 
D)  ($\beta$-helix) 
E)  cylinder

Question 18

What is the pI of the following amino acid?

Accepted Answer

A)  5.56 
B)  6.35 
C)  9.74 
D)  10.53 
E)  none of these 
A)  5.56 
B)  6.35 
C)  9.74 
D)  10.53 
E)  none of these

Question 19

Which of the following amino acids will not migrate towards the cathode/anode at pH 6?
Phenylalanine: pI = 5.5
Leucine: pI = 6

Accepted Answer

The answer of Which of the following amino acids will...

Question 20

Which of the following amino acids will move the farthest when subjected to electrophoresis at pH 7?

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  II and III 
E)  none of these 
A)  I 
B)  II 
C)  III 
D)  II and III 
E)  none of these

Exam 25: Amino Acids, Peptides, and Proteins

α\alphaα -Keratin found in nails has more strength than α\alphaα -keratin found in hair due to the presence of more ___________.

Which of the following is a correct structure for D-leucine?

Provide the structure of the amino acid produced from the following reaction.

Which of the following alkenes is used to prepare isoleucine using an asymmetric catalytic hydrogenation reaction?

Which of the following amino acids will migrate towards the anode at pH 7? Glycine: pI = 6.0 Lysine: pI = 9.7

Which of the following results after three steps of Edman degradation of the heptapeptide Lys-His-Gly-Phe-Tyr-Ser-Ala?

Proteins that catalyze biochemical reactions are called ______.

How do enzymes speed up a reaction?

Amino acids are considered amphoteric because _____________.

Draw the Fischer projection for L-aspartic acid and assign the configuration (R/S) at the chirality center.

Which amino acid is produced from the following reaction sequence?

Denaturation is ______.

Which of the following amino acids contain a polar side chain?

Which amino acid is produced from the following reaction sequence?

Which of the following is the correct sequence of the tetrapeptide that is formed by the following reaction sequence?

What is the correct sequence of amino acids for the following tripeptide?

Which of the following is a major component of the secondary structure of keratin found in hair?

What is the pI of the following amino acid?

Which of the following amino acids will not migrate towards the cathode/anode at pH 6? Phenylalanine: pI = 5.5 Leucine: pI = 6

Which of the following amino acids will move the farthest when subjected to electrophoresis at pH 7?

A Review of General Chemistry: Electrons, Bonds, and Molecular Properties

Molecular Representations

Acids and Bases

Alkanes and Cycloalkanes

Stereoisomerism

Chemical Reactivity and Mechanisms

Alkyl Halides: Nucleophilic Substitution and Elimination Reactions

Addition Reactions of Alkenes

Alkynes

Radical Reactions

Synthesis

Alcohols and Phenols

Ethers and Epoxides; Thiols and Sulfides

Infrared Spectroscopy and Mass Spectrometry

Nuclear Magnetic Resonance Spectroscopy

Conjugated Pi Systems and Pericyclic Reactions

Aromatic Compounds

Aromatic Substitution Reactions

Aldehydes and Ketones

Carboxylic Acids and Their Derivatives

Alpha Carbon Chemistry: Enols and Enolates

Amines

Introduction to Organometallic Compounds

Carbohydrates

Lipids

Synthetic Polymers

Filters

$\alpha$ -Keratin found in nails has more strength than $\alpha$ -keratin found in hair due to the presence of more ___________.