(a) Interpretation: The explanation for alanine which has different optical rotation in water, 1 M HCl , and 1 M NaOH is to be stated. Concept introduction: The amino acid is made of two functional groups an amine group, − NH 2 and a carboxyl group, − COOH . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid alanine contains a − CH 3 side chain.

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Answer 1

Question

Chapter 27, Problem 27.61AP

Interpretation Introduction

(a)

Interpretation:

The explanation for alanine which has different optical rotation in water, $1 M$ $HCl$ , and $1 M$ $NaOH$ is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid alanine contains a $−CH3$ side chain.

Expert Solution

Answer to Problem 27.61AP

Each solvent rotates the alanine molecule to a different angle due to the formation of different complex formation and so it gives rise to different optical rotation in different solvents.

Explanation of Solution

The structure of alanine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 1

Figure 1

Alanine is an optically active compound. It rotates the plane of polarized light. The reaction of alanine with water, $1 M$ $HCl$ , and $1 M$ $NaOH$ forms a complex which is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 2

Figure 2

The optical rotation of alanine is measure by Circular Dichroism (CD). It involves circularly polarized light absorption. It measures the angle at which the plane-polarized light is rotated by the molecule. Each solvent rotates the alanine molecule to a different angle, due to this it gives rise to different optical rotation in different solvents.

Conclusion

The alanine has different optical rotation in water, $1 M$ $HCl$ , and $1 M$ $NaOH$ . This is because of different solvent molecule rotates the alanine molecule to a different angle.

Interpretation Introduction

(b)

Interpretation:

The explanation for two known mono $−N−$ acetyl derivatives of lysine is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid lysine contains a $−(CH2)4NH2$ side chain.

Expert Solution

Answer to Problem 27.61AP

Due to the presence of two amine groups in lysine molecule. It may undergo acetylation reaction from either side and form mono $−N−$ acetyl derivatives of lysine.

Explanation of Solution

The structure of amino acid lysine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 3

Figure 3

The structure of the lysine molecule contains two amine group one at the $α$ carbon and other at the side chain. Therefore, it has the potential to undergo acetylation reaction from two sides which results in the formation of two mono $−N−$ acetyl derivatives of lysine. The product obtained after the acetylation reaction of lysine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 4

Figure 4

Conclusion

The two mono $−N−$ acetyl derivatives of lysine are possible. This is because of the presence of two amine groups which undergo acetylation reaction from either side and form mono $−N−$ acetyl derivatives of lysine.

Interpretation Introduction

(c)

Interpretation:

The explanation for fact that the peptide $Gly−Ala−Arg−Ala−Glu$ which is hydrolyzed by trypsin in water at $pH=8$ but remains inert to trypsin in $8 M$ urea $pH=8$ is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group $−NH2$ and a carboxyl group $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. Urea at basic conditions is known to be a denaturation agent of protein.

Expert Solution

Answer to Problem 27.61AP

The compound urea under basic conditions acts as a denaturation agent which breakdown the protein molecule bonding. Due to this, the peptide, $Gly−Ala−Arg−Ala−Glu$ which is hydrolyzed by trypsin in the water at $pH=8$ but remains inert to trypsin in $8 M$ urea $pH=8$ .

Explanation of Solution

The protein molecule is composed of four types of structure primary, secondary, tertiary and quarternary. The enzyme trypsin hydrolyzes the peptide, $Gly−Ala−Arg−Ala−Glu$ in the water at $pH=8$ which results in the dissociation of an amide linkage. When the same peptide is treated with urea at same $pH$ , it breaks the tertiary and quarternary structure of the protein and does not hydrolyze the peptide. It causes denaturation of protein by breaking the internal hydrogen bonding of the protein molecule.

Conclusion

The peptide $Gly−Ala−Arg−Ala−Glu$ which is hydrolyzed by trypsin in the water at $pH=8$ but remains inert to trypsin in $8 M$ urea $pH=8$ . This is because of urea under basic conditions acts as a denaturation agent which breakdown the protein molecule bonding.

Interpretation Introduction

(d)

Interpretation:

The explanation for the peptide containing cysteine on reaction with $HSCH2CH2OH$ and aziridine may cleaved by trypsin at the modified cysteine residue is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid cysteine contains a $−CH2SH$ side chain.

Expert Solution

Answer to Problem 27.61AP

The generation of lysine type molecule at the end of the reaction which is cleaved by trypsin enzyme. Due to this, the peptide containing cysteine on reaction with $HSCH2CH2OH$ and aziridine may cleaved by trypsin at the modified cysteine residue.

Explanation of Solution

The structure of the cysteine molecule is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 5

Figure 5

The same molecule in peptides exists as a disulfide bond. The disulfide bond of cysteine in the protein molecule is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 6

Figure 6

When this protein molecule with a disulfide bond is treated with $HSCH2CH2OH$ which dissociates the disulfide bond. It results in the formation of a thiol group and $2,2'−disulfanediyldiethanol$ . The reaction of a disulfide bond with $HSCH2CH2OH$ is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 7

Figure 7

The thiol group is then reacted with the aziridine molecule which results in the formation of a lysine type molecule. This reaction is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 8

Figure 8

This lysine type molecule then reacts with trypsin enzyme which cleaves arginine and lysine molecule. Due to this, the trypsin enzyme reacts with the modified cysteine residues.

Conclusion

The peptide containing cysteine on reaction with $HSCH2CH2OH$ and aziridine may cleaved by trypsin at the modified cysteine residue. This is because of the generation of lysine type molecule at the end of the reaction which is cleaved by trypsin enzyme.

Interpretation Introduction

(e)

Interpretation:

The explanation for the formation of two separable methionine sulfoxides from the oxidation of $L−methionine$ with $H2O2$ is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid methionine contains $−CH2CH2SCH3$ side chain.

Expert Solution

Answer to Problem 27.61AP

The application of a certain amount of energy which converts one form to another form of structure. Due to this, the formation of two separable methionine sulfoxides from the oxidation of $L−methionine$ with $H2O2$ is possible.

Explanation of Solution

The structure of methionine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 9

Figure 9

The resonance structure of sulfoxides with two different groups is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 10

Figure 10

The conversion of one structure to another structure at room temperature requires a certain amount of energy. Therefore, on the application of that amount of energy, the two forms of $L−methionine$ which are separable at room temperature are formed. The structure of two different forms of $L−methionine$ is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 11

Figure 11

Conclusion

The formation of two separable methionine sulfoxides from the oxidation of $L−methionine$ with $H2O2$ is possible. This is because of the application of a certain amount of energy which converts one form to another form of structure. They are separable at room temperature.

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Answer 2

Question

Chapter 27, Problem 27.61AP

Interpretation Introduction

(a)

Interpretation:

The explanation for alanine which has different optical rotation in water, $1 M$ $HCl$ , and $1 M$ $NaOH$ is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid alanine contains a $−CH3$ side chain.

Expert Solution

Answer to Problem 27.61AP

Each solvent rotates the alanine molecule to a different angle due to the formation of different complex formation and so it gives rise to different optical rotation in different solvents.

Explanation of Solution

The structure of alanine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 1

Figure 1

Alanine is an optically active compound. It rotates the plane of polarized light. The reaction of alanine with water, $1 M$ $HCl$ , and $1 M$ $NaOH$ forms a complex which is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 2

Figure 2

The optical rotation of alanine is measure by Circular Dichroism (CD). It involves circularly polarized light absorption. It measures the angle at which the plane-polarized light is rotated by the molecule. Each solvent rotates the alanine molecule to a different angle, due to this it gives rise to different optical rotation in different solvents.

Conclusion

The alanine has different optical rotation in water, $1 M$ $HCl$ , and $1 M$ $NaOH$ . This is because of different solvent molecule rotates the alanine molecule to a different angle.

Interpretation Introduction

(b)

Interpretation:

The explanation for two known mono $−N−$ acetyl derivatives of lysine is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid lysine contains a $−(CH2)4NH2$ side chain.

Expert Solution

Answer to Problem 27.61AP

Due to the presence of two amine groups in lysine molecule. It may undergo acetylation reaction from either side and form mono $−N−$ acetyl derivatives of lysine.

Explanation of Solution

The structure of amino acid lysine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 3

Figure 3

The structure of the lysine molecule contains two amine group one at the $α$ carbon and other at the side chain. Therefore, it has the potential to undergo acetylation reaction from two sides which results in the formation of two mono $−N−$ acetyl derivatives of lysine. The product obtained after the acetylation reaction of lysine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 4

Figure 4

Conclusion

The two mono $−N−$ acetyl derivatives of lysine are possible. This is because of the presence of two amine groups which undergo acetylation reaction from either side and form mono $−N−$ acetyl derivatives of lysine.

Interpretation Introduction

(c)

Interpretation:

The explanation for fact that the peptide $Gly−Ala−Arg−Ala−Glu$ which is hydrolyzed by trypsin in water at $pH=8$ but remains inert to trypsin in $8 M$ urea $pH=8$ is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group $−NH2$ and a carboxyl group $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. Urea at basic conditions is known to be a denaturation agent of protein.

Expert Solution

Answer to Problem 27.61AP

The compound urea under basic conditions acts as a denaturation agent which breakdown the protein molecule bonding. Due to this, the peptide, $Gly−Ala−Arg−Ala−Glu$ which is hydrolyzed by trypsin in the water at $pH=8$ but remains inert to trypsin in $8 M$ urea $pH=8$ .

Explanation of Solution

The protein molecule is composed of four types of structure primary, secondary, tertiary and quarternary. The enzyme trypsin hydrolyzes the peptide, $Gly−Ala−Arg−Ala−Glu$ in the water at $pH=8$ which results in the dissociation of an amide linkage. When the same peptide is treated with urea at same $pH$ , it breaks the tertiary and quarternary structure of the protein and does not hydrolyze the peptide. It causes denaturation of protein by breaking the internal hydrogen bonding of the protein molecule.

Conclusion

The peptide $Gly−Ala−Arg−Ala−Glu$ which is hydrolyzed by trypsin in the water at $pH=8$ but remains inert to trypsin in $8 M$ urea $pH=8$ . This is because of urea under basic conditions acts as a denaturation agent which breakdown the protein molecule bonding.

Interpretation Introduction

(d)

Interpretation:

The explanation for the peptide containing cysteine on reaction with $HSCH2CH2OH$ and aziridine may cleaved by trypsin at the modified cysteine residue is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid cysteine contains a $−CH2SH$ side chain.

Expert Solution

Answer to Problem 27.61AP

The generation of lysine type molecule at the end of the reaction which is cleaved by trypsin enzyme. Due to this, the peptide containing cysteine on reaction with $HSCH2CH2OH$ and aziridine may cleaved by trypsin at the modified cysteine residue.

Explanation of Solution

The structure of the cysteine molecule is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 5

Figure 5

The same molecule in peptides exists as a disulfide bond. The disulfide bond of cysteine in the protein molecule is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 6

Figure 6

When this protein molecule with a disulfide bond is treated with $HSCH2CH2OH$ which dissociates the disulfide bond. It results in the formation of a thiol group and $2,2'−disulfanediyldiethanol$ . The reaction of a disulfide bond with $HSCH2CH2OH$ is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 7

Figure 7

The thiol group is then reacted with the aziridine molecule which results in the formation of a lysine type molecule. This reaction is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 8

Figure 8

This lysine type molecule then reacts with trypsin enzyme which cleaves arginine and lysine molecule. Due to this, the trypsin enzyme reacts with the modified cysteine residues.

Conclusion

The peptide containing cysteine on reaction with $HSCH2CH2OH$ and aziridine may cleaved by trypsin at the modified cysteine residue. This is because of the generation of lysine type molecule at the end of the reaction which is cleaved by trypsin enzyme.

Interpretation Introduction

(e)

Interpretation:

The explanation for the formation of two separable methionine sulfoxides from the oxidation of $L−methionine$ with $H2O2$ is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid methionine contains $−CH2CH2SCH3$ side chain.

Expert Solution

Answer to Problem 27.61AP

The application of a certain amount of energy which converts one form to another form of structure. Due to this, the formation of two separable methionine sulfoxides from the oxidation of $L−methionine$ with $H2O2$ is possible.

Explanation of Solution

The structure of methionine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 9

Figure 9

The resonance structure of sulfoxides with two different groups is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 10

Figure 10

The conversion of one structure to another structure at room temperature requires a certain amount of energy. Therefore, on the application of that amount of energy, the two forms of $L−methionine$ which are separable at room temperature are formed. The structure of two different forms of $L−methionine$ is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 11

Figure 11

Conclusion

The formation of two separable methionine sulfoxides from the oxidation of $L−methionine$ with $H2O2$ is possible. This is because of the application of a certain amount of energy which converts one form to another form of structure. They are separable at room temperature.

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Answer 3

Question

Chapter 27, Problem 27.61AP

Interpretation Introduction

(a)

Interpretation:

The explanation for alanine which has different optical rotation in water, $1 M$ $HCl$ , and $1 M$ $NaOH$ is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid alanine contains a $−CH3$ side chain.

Expert Solution

Answer to Problem 27.61AP

Each solvent rotates the alanine molecule to a different angle due to the formation of different complex formation and so it gives rise to different optical rotation in different solvents.

Explanation of Solution

The structure of alanine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 1

Figure 1

Alanine is an optically active compound. It rotates the plane of polarized light. The reaction of alanine with water, $1 M$ $HCl$ , and $1 M$ $NaOH$ forms a complex which is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 2

Figure 2

The optical rotation of alanine is measure by Circular Dichroism (CD). It involves circularly polarized light absorption. It measures the angle at which the plane-polarized light is rotated by the molecule. Each solvent rotates the alanine molecule to a different angle, due to this it gives rise to different optical rotation in different solvents.

Conclusion

The alanine has different optical rotation in water, $1 M$ $HCl$ , and $1 M$ $NaOH$ . This is because of different solvent molecule rotates the alanine molecule to a different angle.

Interpretation Introduction

(b)

Interpretation:

The explanation for two known mono $−N−$ acetyl derivatives of lysine is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid lysine contains a $−(CH2)4NH2$ side chain.

Expert Solution

Answer to Problem 27.61AP

Due to the presence of two amine groups in lysine molecule. It may undergo acetylation reaction from either side and form mono $−N−$ acetyl derivatives of lysine.

Explanation of Solution

The structure of amino acid lysine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 3

Figure 3

The structure of the lysine molecule contains two amine group one at the $α$ carbon and other at the side chain. Therefore, it has the potential to undergo acetylation reaction from two sides which results in the formation of two mono $−N−$ acetyl derivatives of lysine. The product obtained after the acetylation reaction of lysine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 4

Figure 4

Conclusion

The two mono $−N−$ acetyl derivatives of lysine are possible. This is because of the presence of two amine groups which undergo acetylation reaction from either side and form mono $−N−$ acetyl derivatives of lysine.

Interpretation Introduction

(c)

Interpretation:

The explanation for fact that the peptide $Gly−Ala−Arg−Ala−Glu$ which is hydrolyzed by trypsin in water at $pH=8$ but remains inert to trypsin in $8 M$ urea $pH=8$ is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group $−NH2$ and a carboxyl group $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. Urea at basic conditions is known to be a denaturation agent of protein.

Expert Solution

Answer to Problem 27.61AP

The compound urea under basic conditions acts as a denaturation agent which breakdown the protein molecule bonding. Due to this, the peptide, $Gly−Ala−Arg−Ala−Glu$ which is hydrolyzed by trypsin in the water at $pH=8$ but remains inert to trypsin in $8 M$ urea $pH=8$ .

Explanation of Solution

The protein molecule is composed of four types of structure primary, secondary, tertiary and quarternary. The enzyme trypsin hydrolyzes the peptide, $Gly−Ala−Arg−Ala−Glu$ in the water at $pH=8$ which results in the dissociation of an amide linkage. When the same peptide is treated with urea at same $pH$ , it breaks the tertiary and quarternary structure of the protein and does not hydrolyze the peptide. It causes denaturation of protein by breaking the internal hydrogen bonding of the protein molecule.

Conclusion

The peptide $Gly−Ala−Arg−Ala−Glu$ which is hydrolyzed by trypsin in the water at $pH=8$ but remains inert to trypsin in $8 M$ urea $pH=8$ . This is because of urea under basic conditions acts as a denaturation agent which breakdown the protein molecule bonding.

Interpretation Introduction

(d)

Interpretation:

The explanation for the peptide containing cysteine on reaction with $HSCH2CH2OH$ and aziridine may cleaved by trypsin at the modified cysteine residue is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid cysteine contains a $−CH2SH$ side chain.

Expert Solution

Answer to Problem 27.61AP

The generation of lysine type molecule at the end of the reaction which is cleaved by trypsin enzyme. Due to this, the peptide containing cysteine on reaction with $HSCH2CH2OH$ and aziridine may cleaved by trypsin at the modified cysteine residue.

Explanation of Solution

The structure of the cysteine molecule is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 5

Figure 5

The same molecule in peptides exists as a disulfide bond. The disulfide bond of cysteine in the protein molecule is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 6

Figure 6

When this protein molecule with a disulfide bond is treated with $HSCH2CH2OH$ which dissociates the disulfide bond. It results in the formation of a thiol group and $2,2'−disulfanediyldiethanol$ . The reaction of a disulfide bond with $HSCH2CH2OH$ is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 7

Figure 7

The thiol group is then reacted with the aziridine molecule which results in the formation of a lysine type molecule. This reaction is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 8

Figure 8

This lysine type molecule then reacts with trypsin enzyme which cleaves arginine and lysine molecule. Due to this, the trypsin enzyme reacts with the modified cysteine residues.

Conclusion

The peptide containing cysteine on reaction with $HSCH2CH2OH$ and aziridine may cleaved by trypsin at the modified cysteine residue. This is because of the generation of lysine type molecule at the end of the reaction which is cleaved by trypsin enzyme.

Interpretation Introduction

(e)

Interpretation:

The explanation for the formation of two separable methionine sulfoxides from the oxidation of $L−methionine$ with $H2O2$ is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid methionine contains $−CH2CH2SCH3$ side chain.

Expert Solution

Answer to Problem 27.61AP

The application of a certain amount of energy which converts one form to another form of structure. Due to this, the formation of two separable methionine sulfoxides from the oxidation of $L−methionine$ with $H2O2$ is possible.

Explanation of Solution

The structure of methionine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 9

Figure 9

The resonance structure of sulfoxides with two different groups is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 10

Figure 10

The conversion of one structure to another structure at room temperature requires a certain amount of energy. Therefore, on the application of that amount of energy, the two forms of $L−methionine$ which are separable at room temperature are formed. The structure of two different forms of $L−methionine$ is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 11

Figure 11

Conclusion

The formation of two separable methionine sulfoxides from the oxidation of $L−methionine$ with $H2O2$ is possible. This is because of the application of a certain amount of energy which converts one form to another form of structure. They are separable at room temperature.

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Answer 4

Question

Chapter 27, Problem 27.61AP

Interpretation Introduction

(a)

Interpretation:

The explanation for alanine which has different optical rotation in water, $1 M$ $HCl$ , and $1 M$ $NaOH$ is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid alanine contains a $−CH3$ side chain.

Expert Solution

Answer to Problem 27.61AP

Each solvent rotates the alanine molecule to a different angle due to the formation of different complex formation and so it gives rise to different optical rotation in different solvents.

Explanation of Solution

The structure of alanine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 1

Figure 1

Alanine is an optically active compound. It rotates the plane of polarized light. The reaction of alanine with water, $1 M$ $HCl$ , and $1 M$ $NaOH$ forms a complex which is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 2

Figure 2

The optical rotation of alanine is measure by Circular Dichroism (CD). It involves circularly polarized light absorption. It measures the angle at which the plane-polarized light is rotated by the molecule. Each solvent rotates the alanine molecule to a different angle, due to this it gives rise to different optical rotation in different solvents.

Conclusion

The alanine has different optical rotation in water, $1 M$ $HCl$ , and $1 M$ $NaOH$ . This is because of different solvent molecule rotates the alanine molecule to a different angle.

Interpretation Introduction

(b)

Interpretation:

The explanation for two known mono $−N−$ acetyl derivatives of lysine is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid lysine contains a $−(CH2)4NH2$ side chain.

Expert Solution

Answer to Problem 27.61AP

Due to the presence of two amine groups in lysine molecule. It may undergo acetylation reaction from either side and form mono $−N−$ acetyl derivatives of lysine.

Explanation of Solution

The structure of amino acid lysine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 3

Figure 3

The structure of the lysine molecule contains two amine group one at the $α$ carbon and other at the side chain. Therefore, it has the potential to undergo acetylation reaction from two sides which results in the formation of two mono $−N−$ acetyl derivatives of lysine. The product obtained after the acetylation reaction of lysine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 4

Figure 4

Conclusion

The two mono $−N−$ acetyl derivatives of lysine are possible. This is because of the presence of two amine groups which undergo acetylation reaction from either side and form mono $−N−$ acetyl derivatives of lysine.

Interpretation Introduction

(c)

Interpretation:

The explanation for fact that the peptide $Gly−Ala−Arg−Ala−Glu$ which is hydrolyzed by trypsin in water at $pH=8$ but remains inert to trypsin in $8 M$ urea $pH=8$ is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group $−NH2$ and a carboxyl group $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. Urea at basic conditions is known to be a denaturation agent of protein.

Expert Solution

Answer to Problem 27.61AP

The compound urea under basic conditions acts as a denaturation agent which breakdown the protein molecule bonding. Due to this, the peptide, $Gly−Ala−Arg−Ala−Glu$ which is hydrolyzed by trypsin in the water at $pH=8$ but remains inert to trypsin in $8 M$ urea $pH=8$ .

Explanation of Solution

The protein molecule is composed of four types of structure primary, secondary, tertiary and quarternary. The enzyme trypsin hydrolyzes the peptide, $Gly−Ala−Arg−Ala−Glu$ in the water at $pH=8$ which results in the dissociation of an amide linkage. When the same peptide is treated with urea at same $pH$ , it breaks the tertiary and quarternary structure of the protein and does not hydrolyze the peptide. It causes denaturation of protein by breaking the internal hydrogen bonding of the protein molecule.

Conclusion

The peptide $Gly−Ala−Arg−Ala−Glu$ which is hydrolyzed by trypsin in the water at $pH=8$ but remains inert to trypsin in $8 M$ urea $pH=8$ . This is because of urea under basic conditions acts as a denaturation agent which breakdown the protein molecule bonding.

Interpretation Introduction

(d)

Interpretation:

The explanation for the peptide containing cysteine on reaction with $HSCH2CH2OH$ and aziridine may cleaved by trypsin at the modified cysteine residue is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid cysteine contains a $−CH2SH$ side chain.

Expert Solution

Answer to Problem 27.61AP

The generation of lysine type molecule at the end of the reaction which is cleaved by trypsin enzyme. Due to this, the peptide containing cysteine on reaction with $HSCH2CH2OH$ and aziridine may cleaved by trypsin at the modified cysteine residue.

Explanation of Solution

The structure of the cysteine molecule is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 5

Figure 5

The same molecule in peptides exists as a disulfide bond. The disulfide bond of cysteine in the protein molecule is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 6

Figure 6

When this protein molecule with a disulfide bond is treated with $HSCH2CH2OH$ which dissociates the disulfide bond. It results in the formation of a thiol group and $2,2'−disulfanediyldiethanol$ . The reaction of a disulfide bond with $HSCH2CH2OH$ is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 7

Figure 7

The thiol group is then reacted with the aziridine molecule which results in the formation of a lysine type molecule. This reaction is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 8

Figure 8

This lysine type molecule then reacts with trypsin enzyme which cleaves arginine and lysine molecule. Due to this, the trypsin enzyme reacts with the modified cysteine residues.

Conclusion

The peptide containing cysteine on reaction with $HSCH2CH2OH$ and aziridine may cleaved by trypsin at the modified cysteine residue. This is because of the generation of lysine type molecule at the end of the reaction which is cleaved by trypsin enzyme.

Interpretation Introduction

(e)

Interpretation:

The explanation for the formation of two separable methionine sulfoxides from the oxidation of $L−methionine$ with $H2O2$ is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid methionine contains $−CH2CH2SCH3$ side chain.

Expert Solution

Answer to Problem 27.61AP

The application of a certain amount of energy which converts one form to another form of structure. Due to this, the formation of two separable methionine sulfoxides from the oxidation of $L−methionine$ with $H2O2$ is possible.

Explanation of Solution

The structure of methionine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 9

Figure 9

The resonance structure of sulfoxides with two different groups is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 10

Figure 10

The conversion of one structure to another structure at room temperature requires a certain amount of energy. Therefore, on the application of that amount of energy, the two forms of $L−methionine$ which are separable at room temperature are formed. The structure of two different forms of $L−methionine$ is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 11

Figure 11

Conclusion

The formation of two separable methionine sulfoxides from the oxidation of $L−methionine$ with $H2O2$ is possible. This is because of the application of a certain amount of energy which converts one form to another form of structure. They are separable at room temperature.

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Answer 5

Chapter 27, Problem 27.61AP

Interpretation Introduction

(a)

Interpretation:

The explanation for alanine which has different optical rotation in water, $1 M$ $HCl$ , and $1 M$ $NaOH$ is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid alanine contains a $−CH3$ side chain.

Expert Solution

Answer to Problem 27.61AP

Each solvent rotates the alanine molecule to a different angle due to the formation of different complex formation and so it gives rise to different optical rotation in different solvents.

Explanation of Solution

The structure of alanine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 1

Figure 1

Alanine is an optically active compound. It rotates the plane of polarized light. The reaction of alanine with water, $1 M$ $HCl$ , and $1 M$ $NaOH$ forms a complex which is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 2

Figure 2

The optical rotation of alanine is measure by Circular Dichroism (CD). It involves circularly polarized light absorption. It measures the angle at which the plane-polarized light is rotated by the molecule. Each solvent rotates the alanine molecule to a different angle, due to this it gives rise to different optical rotation in different solvents.

Conclusion

The alanine has different optical rotation in water, $1 M$ $HCl$ , and $1 M$ $NaOH$ . This is because of different solvent molecule rotates the alanine molecule to a different angle.

Interpretation Introduction

(b)

Interpretation:

The explanation for two known mono $−N−$ acetyl derivatives of lysine is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid lysine contains a $−(CH2)4NH2$ side chain.

Expert Solution

Answer to Problem 27.61AP

Due to the presence of two amine groups in lysine molecule. It may undergo acetylation reaction from either side and form mono $−N−$ acetyl derivatives of lysine.

Explanation of Solution

The structure of amino acid lysine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 3

Figure 3

The structure of the lysine molecule contains two amine group one at the $α$ carbon and other at the side chain. Therefore, it has the potential to undergo acetylation reaction from two sides which results in the formation of two mono $−N−$ acetyl derivatives of lysine. The product obtained after the acetylation reaction of lysine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 4

Figure 4

Conclusion

The two mono $−N−$ acetyl derivatives of lysine are possible. This is because of the presence of two amine groups which undergo acetylation reaction from either side and form mono $−N−$ acetyl derivatives of lysine.

Interpretation Introduction

(c)

Interpretation:

The explanation for fact that the peptide $Gly−Ala−Arg−Ala−Glu$ which is hydrolyzed by trypsin in water at $pH=8$ but remains inert to trypsin in $8 M$ urea $pH=8$ is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group $−NH2$ and a carboxyl group $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. Urea at basic conditions is known to be a denaturation agent of protein.

Expert Solution

Answer to Problem 27.61AP

The compound urea under basic conditions acts as a denaturation agent which breakdown the protein molecule bonding. Due to this, the peptide, $Gly−Ala−Arg−Ala−Glu$ which is hydrolyzed by trypsin in the water at $pH=8$ but remains inert to trypsin in $8 M$ urea $pH=8$ .

Explanation of Solution

The protein molecule is composed of four types of structure primary, secondary, tertiary and quarternary. The enzyme trypsin hydrolyzes the peptide, $Gly−Ala−Arg−Ala−Glu$ in the water at $pH=8$ which results in the dissociation of an amide linkage. When the same peptide is treated with urea at same $pH$ , it breaks the tertiary and quarternary structure of the protein and does not hydrolyze the peptide. It causes denaturation of protein by breaking the internal hydrogen bonding of the protein molecule.

Conclusion

The peptide $Gly−Ala−Arg−Ala−Glu$ which is hydrolyzed by trypsin in the water at $pH=8$ but remains inert to trypsin in $8 M$ urea $pH=8$ . This is because of urea under basic conditions acts as a denaturation agent which breakdown the protein molecule bonding.

Interpretation Introduction

(d)

Interpretation:

The explanation for the peptide containing cysteine on reaction with $HSCH2CH2OH$ and aziridine may cleaved by trypsin at the modified cysteine residue is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid cysteine contains a $−CH2SH$ side chain.

Expert Solution

Answer to Problem 27.61AP

The generation of lysine type molecule at the end of the reaction which is cleaved by trypsin enzyme. Due to this, the peptide containing cysteine on reaction with $HSCH2CH2OH$ and aziridine may cleaved by trypsin at the modified cysteine residue.

Explanation of Solution

The structure of the cysteine molecule is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 5

Figure 5

The same molecule in peptides exists as a disulfide bond. The disulfide bond of cysteine in the protein molecule is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 6

Figure 6

When this protein molecule with a disulfide bond is treated with $HSCH2CH2OH$ which dissociates the disulfide bond. It results in the formation of a thiol group and $2,2'−disulfanediyldiethanol$ . The reaction of a disulfide bond with $HSCH2CH2OH$ is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 7

Figure 7

The thiol group is then reacted with the aziridine molecule which results in the formation of a lysine type molecule. This reaction is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 8

Figure 8

This lysine type molecule then reacts with trypsin enzyme which cleaves arginine and lysine molecule. Due to this, the trypsin enzyme reacts with the modified cysteine residues.

Conclusion

The peptide containing cysteine on reaction with $HSCH2CH2OH$ and aziridine may cleaved by trypsin at the modified cysteine residue. This is because of the generation of lysine type molecule at the end of the reaction which is cleaved by trypsin enzyme.

Interpretation Introduction

(e)

Interpretation:

The explanation for the formation of two separable methionine sulfoxides from the oxidation of $L−methionine$ with $H2O2$ is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid methionine contains $−CH2CH2SCH3$ side chain.

Expert Solution

Answer to Problem 27.61AP

The application of a certain amount of energy which converts one form to another form of structure. Due to this, the formation of two separable methionine sulfoxides from the oxidation of $L−methionine$ with $H2O2$ is possible.

Explanation of Solution

The structure of methionine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 9

Figure 9

The resonance structure of sulfoxides with two different groups is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 10

Figure 10

The conversion of one structure to another structure at room temperature requires a certain amount of energy. Therefore, on the application of that amount of energy, the two forms of $L−methionine$ which are separable at room temperature are formed. The structure of two different forms of $L−methionine$ is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 11

Figure 11

Conclusion

The formation of two separable methionine sulfoxides from the oxidation of $L−methionine$ with $H2O2$ is possible. This is because of the application of a certain amount of energy which converts one form to another form of structure. They are separable at room temperature.

Answer 6

Chapter 27, Problem 27.61AP

Interpretation Introduction

(a)

Interpretation:

The explanation for alanine which has different optical rotation in water, $1 M$ $HCl$ , and $1 M$ $NaOH$ is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid alanine contains a $−CH3$ side chain.

Expert Solution

Answer to Problem 27.61AP

Each solvent rotates the alanine molecule to a different angle due to the formation of different complex formation and so it gives rise to different optical rotation in different solvents.

Explanation of Solution

The structure of alanine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 1

Figure 1

Alanine is an optically active compound. It rotates the plane of polarized light. The reaction of alanine with water, $1 M$ $HCl$ , and $1 M$ $NaOH$ forms a complex which is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 2

Figure 2

The optical rotation of alanine is measure by Circular Dichroism (CD). It involves circularly polarized light absorption. It measures the angle at which the plane-polarized light is rotated by the molecule. Each solvent rotates the alanine molecule to a different angle, due to this it gives rise to different optical rotation in different solvents.

Conclusion

The alanine has different optical rotation in water, $1 M$ $HCl$ , and $1 M$ $NaOH$ . This is because of different solvent molecule rotates the alanine molecule to a different angle.

Answer 7

Chapter 27, Problem 27.61AP

Interpretation Introduction

(a)

Interpretation:

The explanation for alanine which has different optical rotation in water, $1 M$ $HCl$ , and $1 M$ $NaOH$ is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid alanine contains a $−CH3$ side chain.

Answer 8

Expert Solution

Answer to Problem 27.61AP

Each solvent rotates the alanine molecule to a different angle due to the formation of different complex formation and so it gives rise to different optical rotation in different solvents.

Answer 9

Expert Solution

Answer 10

Expert Solution

Answer 11

Expert Solution

Answer 12

Explanation of Solution

The structure of alanine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 1

Figure 1

Alanine is an optically active compound. It rotates the plane of polarized light. The reaction of alanine with water, $1 M$ $HCl$ , and $1 M$ $NaOH$ forms a complex which is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 2

Figure 2

The optical rotation of alanine is measure by Circular Dichroism (CD). It involves circularly polarized light absorption. It measures the angle at which the plane-polarized light is rotated by the molecule. Each solvent rotates the alanine molecule to a different angle, due to this it gives rise to different optical rotation in different solvents.

Answer 13

Conclusion

The alanine has different optical rotation in water, $1 M$ $HCl$ , and $1 M$ $NaOH$ . This is because of different solvent molecule rotates the alanine molecule to a different angle.

Answer 14

Interpretation Introduction

(b)

Interpretation:

The explanation for two known mono $−N−$ acetyl derivatives of lysine is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid lysine contains a $−(CH2)4NH2$ side chain.

Expert Solution

Answer to Problem 27.61AP

Due to the presence of two amine groups in lysine molecule. It may undergo acetylation reaction from either side and form mono $−N−$ acetyl derivatives of lysine.

Explanation of Solution

The structure of amino acid lysine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 3

Figure 3

The structure of the lysine molecule contains two amine group one at the $α$ carbon and other at the side chain. Therefore, it has the potential to undergo acetylation reaction from two sides which results in the formation of two mono $−N−$ acetyl derivatives of lysine. The product obtained after the acetylation reaction of lysine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 4

Figure 4

Conclusion

The two mono $−N−$ acetyl derivatives of lysine are possible. This is because of the presence of two amine groups which undergo acetylation reaction from either side and form mono $−N−$ acetyl derivatives of lysine.

Answer 15

Interpretation Introduction

(b)

Interpretation:

The explanation for two known mono $−N−$ acetyl derivatives of lysine is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid lysine contains a $−(CH2)4NH2$ side chain.

Answer 16

Expert Solution

Answer to Problem 27.61AP

Due to the presence of two amine groups in lysine molecule. It may undergo acetylation reaction from either side and form mono $−N−$ acetyl derivatives of lysine.

Answer 17

Expert Solution

Answer 18

Expert Solution

Answer 19

Expert Solution

Answer 20

Explanation of Solution

The structure of amino acid lysine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 3

Figure 3

The structure of the lysine molecule contains two amine group one at the $α$ carbon and other at the side chain. Therefore, it has the potential to undergo acetylation reaction from two sides which results in the formation of two mono $−N−$ acetyl derivatives of lysine. The product obtained after the acetylation reaction of lysine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 4

Figure 4

Answer 21

Conclusion

The two mono $−N−$ acetyl derivatives of lysine are possible. This is because of the presence of two amine groups which undergo acetylation reaction from either side and form mono $−N−$ acetyl derivatives of lysine.

Answer 22

Interpretation Introduction

(c)

Interpretation:

The explanation for fact that the peptide $Gly−Ala−Arg−Ala−Glu$ which is hydrolyzed by trypsin in water at $pH=8$ but remains inert to trypsin in $8 M$ urea $pH=8$ is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group $−NH2$ and a carboxyl group $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. Urea at basic conditions is known to be a denaturation agent of protein.

Expert Solution

Answer to Problem 27.61AP

The compound urea under basic conditions acts as a denaturation agent which breakdown the protein molecule bonding. Due to this, the peptide, $Gly−Ala−Arg−Ala−Glu$ which is hydrolyzed by trypsin in the water at $pH=8$ but remains inert to trypsin in $8 M$ urea $pH=8$ .

Explanation of Solution

The protein molecule is composed of four types of structure primary, secondary, tertiary and quarternary. The enzyme trypsin hydrolyzes the peptide, $Gly−Ala−Arg−Ala−Glu$ in the water at $pH=8$ which results in the dissociation of an amide linkage. When the same peptide is treated with urea at same $pH$ , it breaks the tertiary and quarternary structure of the protein and does not hydrolyze the peptide. It causes denaturation of protein by breaking the internal hydrogen bonding of the protein molecule.

Conclusion

The peptide $Gly−Ala−Arg−Ala−Glu$ which is hydrolyzed by trypsin in the water at $pH=8$ but remains inert to trypsin in $8 M$ urea $pH=8$ . This is because of urea under basic conditions acts as a denaturation agent which breakdown the protein molecule bonding.

Answer 23

Interpretation Introduction

(c)

Interpretation:

The explanation for fact that the peptide $Gly−Ala−Arg−Ala−Glu$ which is hydrolyzed by trypsin in water at $pH=8$ but remains inert to trypsin in $8 M$ urea $pH=8$ is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group $−NH2$ and a carboxyl group $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. Urea at basic conditions is known to be a denaturation agent of protein.

Answer 24

Expert Solution

Answer to Problem 27.61AP

The compound urea under basic conditions acts as a denaturation agent which breakdown the protein molecule bonding. Due to this, the peptide, $Gly−Ala−Arg−Ala−Glu$ which is hydrolyzed by trypsin in the water at $pH=8$ but remains inert to trypsin in $8 M$ urea $pH=8$ .

Answer 25

Expert Solution

Answer 26

Expert Solution

Answer 27

Expert Solution

Answer 28

Explanation of Solution

The protein molecule is composed of four types of structure primary, secondary, tertiary and quarternary. The enzyme trypsin hydrolyzes the peptide, $Gly−Ala−Arg−Ala−Glu$ in the water at $pH=8$ which results in the dissociation of an amide linkage. When the same peptide is treated with urea at same $pH$ , it breaks the tertiary and quarternary structure of the protein and does not hydrolyze the peptide. It causes denaturation of protein by breaking the internal hydrogen bonding of the protein molecule.

Answer 29

Conclusion

The peptide $Gly−Ala−Arg−Ala−Glu$ which is hydrolyzed by trypsin in the water at $pH=8$ but remains inert to trypsin in $8 M$ urea $pH=8$ . This is because of urea under basic conditions acts as a denaturation agent which breakdown the protein molecule bonding.

Answer 30

Interpretation Introduction

(d)

Interpretation:

The explanation for the peptide containing cysteine on reaction with $HSCH2CH2OH$ and aziridine may cleaved by trypsin at the modified cysteine residue is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid cysteine contains a $−CH2SH$ side chain.

Expert Solution

Answer to Problem 27.61AP

The generation of lysine type molecule at the end of the reaction which is cleaved by trypsin enzyme. Due to this, the peptide containing cysteine on reaction with $HSCH2CH2OH$ and aziridine may cleaved by trypsin at the modified cysteine residue.

Explanation of Solution

The structure of the cysteine molecule is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 5

Figure 5

The same molecule in peptides exists as a disulfide bond. The disulfide bond of cysteine in the protein molecule is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 6

Figure 6

When this protein molecule with a disulfide bond is treated with $HSCH2CH2OH$ which dissociates the disulfide bond. It results in the formation of a thiol group and $2,2'−disulfanediyldiethanol$ . The reaction of a disulfide bond with $HSCH2CH2OH$ is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 7

Figure 7

The thiol group is then reacted with the aziridine molecule which results in the formation of a lysine type molecule. This reaction is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 8

Figure 8

This lysine type molecule then reacts with trypsin enzyme which cleaves arginine and lysine molecule. Due to this, the trypsin enzyme reacts with the modified cysteine residues.

Conclusion

The peptide containing cysteine on reaction with $HSCH2CH2OH$ and aziridine may cleaved by trypsin at the modified cysteine residue. This is because of the generation of lysine type molecule at the end of the reaction which is cleaved by trypsin enzyme.

Answer 31

Interpretation Introduction

(d)

Interpretation:

The explanation for the peptide containing cysteine on reaction with $HSCH2CH2OH$ and aziridine may cleaved by trypsin at the modified cysteine residue is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid cysteine contains a $−CH2SH$ side chain.

Answer 32

Expert Solution

Answer to Problem 27.61AP

The generation of lysine type molecule at the end of the reaction which is cleaved by trypsin enzyme. Due to this, the peptide containing cysteine on reaction with $HSCH2CH2OH$ and aziridine may cleaved by trypsin at the modified cysteine residue.

Answer 33

Expert Solution

Answer 34

Expert Solution

Answer 35

Expert Solution

Answer 36

Explanation of Solution

The structure of the cysteine molecule is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 5

Figure 5

The same molecule in peptides exists as a disulfide bond. The disulfide bond of cysteine in the protein molecule is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 6

Figure 6

When this protein molecule with a disulfide bond is treated with $HSCH2CH2OH$ which dissociates the disulfide bond. It results in the formation of a thiol group and $2,2'−disulfanediyldiethanol$ . The reaction of a disulfide bond with $HSCH2CH2OH$ is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 7

Figure 7

The thiol group is then reacted with the aziridine molecule which results in the formation of a lysine type molecule. This reaction is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 8

Figure 8

This lysine type molecule then reacts with trypsin enzyme which cleaves arginine and lysine molecule. Due to this, the trypsin enzyme reacts with the modified cysteine residues.

Answer 37

Conclusion

The peptide containing cysteine on reaction with $HSCH2CH2OH$ and aziridine may cleaved by trypsin at the modified cysteine residue. This is because of the generation of lysine type molecule at the end of the reaction which is cleaved by trypsin enzyme.

Answer 38

Interpretation Introduction

(e)

Interpretation:

The explanation for the formation of two separable methionine sulfoxides from the oxidation of $L−methionine$ with $H2O2$ is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid methionine contains $−CH2CH2SCH3$ side chain.

Expert Solution

Answer to Problem 27.61AP

The application of a certain amount of energy which converts one form to another form of structure. Due to this, the formation of two separable methionine sulfoxides from the oxidation of $L−methionine$ with $H2O2$ is possible.

Explanation of Solution

The structure of methionine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 9

Figure 9

The resonance structure of sulfoxides with two different groups is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 10

Figure 10

The conversion of one structure to another structure at room temperature requires a certain amount of energy. Therefore, on the application of that amount of energy, the two forms of $L−methionine$ which are separable at room temperature are formed. The structure of two different forms of $L−methionine$ is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 11

Figure 11

Conclusion

The formation of two separable methionine sulfoxides from the oxidation of $L−methionine$ with $H2O2$ is possible. This is because of the application of a certain amount of energy which converts one form to another form of structure. They are separable at room temperature.

Answer 39

Interpretation Introduction

(e)

Interpretation:

The explanation for the formation of two separable methionine sulfoxides from the oxidation of $L−methionine$ with $H2O2$ is to be stated.

Concept introduction:

The amino acid is made of two functional groups an amine group, $−NH2$ and a carboxyl group, $−COOH$ . Along with a side chain is also attached to the center carbon atom due to which each amino acid is distinguished. The amino acid methionine contains $−CH2CH2SCH3$ side chain.

Answer 40

Expert Solution

Answer to Problem 27.61AP

The application of a certain amount of energy which converts one form to another form of structure. Due to this, the formation of two separable methionine sulfoxides from the oxidation of $L−methionine$ with $H2O2$ is possible.

Answer 41

Expert Solution

Answer 42

Expert Solution

Answer 43

Expert Solution

Answer 44

Explanation of Solution

The structure of methionine is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 9

Figure 9

The resonance structure of sulfoxides with two different groups is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 10

Figure 10

The conversion of one structure to another structure at room temperature requires a certain amount of energy. Therefore, on the application of that amount of energy, the two forms of $L−methionine$ which are separable at room temperature are formed. The structure of two different forms of $L−methionine$ is shown below.

Organic Chemistry, Ebook And Single-course Homework Access, Chapter 27, Problem 27.61AP , additional homework tip 11

Figure 11

Answer 45

Conclusion

The formation of two separable methionine sulfoxides from the oxidation of $L−methionine$ with $H2O2$ is possible. This is because of the application of a certain amount of energy which converts one form to another form of structure. They are separable at room temperature.