Chapter 25.2, Problem 7CC

(a)

Interpretation Introduction

Interpretation:

The pI value for the given set of amino acids needs to be calculated.

Concept introduction:

Amino acids at a particular pH does not migrate in an electric field.  This pH is known as the isoelectric point.  The isoelectric point is also known as isoionic point.  At this isoelectric point the amino acid is neutral.  This means that the zwitterion form predominates more over the other forms.  pI is the isoelectric point and this can be given by average of the pK_a.

$\text{pI=}\frac{{\text{pK}}_{{\text{a}}_{\text{1}}}{\text{+pK}}_{{\text{a}}_{\text{2}}}}{\text{2}}$

To find: the pI value of aspartic acid

(b)

Interpretation Introduction

Interpretation:

The pI value for the given set of amino acids needs to be calculated.

Concept introduction:

Amino acids at a particular pH does not migrate in an electric field.  This pH is known as the isoelectric point.  The isoelectric point is also known as isoionic point.  At this isoelectric point the amino acid is neutral.  This means that the zwitterion form predominates more over the other forms.  pI is the isoelectric point and this can be given by average of the pK_a.

$\text{pI=}\frac{{\text{pK}}_{{\text{a}}_{\text{1}}}{\text{+pK}}_{{\text{a}}_{\text{2}}}}{\text{2}}$

To find : the pI value of leucine

(c)

Interpretation Introduction

Interpretation:

The pI value for the given set of amino acids needs to be calculated.

Concept introduction:

Amino acids at a particular pH does not migrate in an electric field.  This pH is known as the isoelectric point.  The isoelectric point is also known as isoionic point.  At this isoelectric point the amino acid is neutral.  This means that the zwitterion form predominates more over the other forms.  pI is the isoelectric point and this can be given by average of the pK_a.

$\text{pI=}\frac{{\text{pK}}_{{\text{a}}_{\text{1}}}{\text{+pK}}_{{\text{a}}_{\text{2}}}}{\text{2}}$

To find : the pI value of lysine

(d)

Interpretation Introduction

Interpretation:

The pI value for the given set of amino acids needs to be calculated.

Concept introduction:

Amino acids at a particular pH does not migrate in an electric field.  This pH is known as the isoelectric point.  The isoelectric point is also known as isoionic point.  At this isoelectric point the amino acid is neutral.  This means that the zwitterion form predominates more over the other forms.  pI is the isoelectric point and this can be given by average of the pK_a.

$\text{pI=}\frac{{\text{pK}}_{{\text{a}}_{\text{1}}}{\text{+pK}}_{{\text{a}}_{\text{2}}}}{\text{2}}$

To find: the pI value of proline