Chapter 25, Problem 25.51QP

(a)

Interpretation Introduction

Interpretation:

The bonding in disulfide bonds present in protein chains has to be described in terms of hybridization.

(b)

Interpretation Introduction

Interpretation:

From the given list of amino acids in table 25.2 of the text book, the amino acid that contains $-SH$ group has to be has to be identified.

(c)

Interpretation Introduction

Interpretation:

The signs of $\Delta S$ and $\Delta H$ have to be predicted for denaturation process.

Concept Introduction:

• Entropy refers to measurement of randomness or disorderliness in the system.  More the number of molecules in a system more will be the movement of molecules and greater will be the entropy given that weak intermolecular forces prevails between molecules.
• Entropy is denoted by ‘S’ and $\Delta S°$ refers to change in entropy of the system.  $\Delta S°$ value positive for a phenomenon indicates the process is spontaneous.  $\Delta S°$ value negative for a phenomenon indicates the process is non–spontaneous
• The term free energy G, refers to energy available in the system to do work and enthalpy H, refers to heat content of the system.  Change in standard free energy is $\Delta G°$ and change in standard enthalpy is $\Delta H°.$
• All these three parameters are related by an equation,

$\Delta G°=\Delta H°-T\Delta S°$

• Standard free energy change, $\Delta G°,$ is represented as,

$\Delta G°=\Delta H°-T\Delta S°$

       Where,

$\begin{array}{l}\Delta H°=\text{ standard enthalpy change}\\ \Delta \text{S}°\text{= standard entropy change}\end{array}$

• Spontaneous process has – positive entropy value and negative free energy, enthalpy value.
• Non-spontaneous process tends to proceed with negative entropy value and positive free energy and enthalpy.

(d)

Interpretation Introduction

Interpretation:

The fraction of regenerated protein structure that correspond to native form has to be calculated if formation of disulfide bond is random between two SH groups by oxidation.

(e)

Interpretation Introduction

Interpretation:

The chemical basis for the reaction involving in deodorizing a dog with hydrogen peroxide solution has to be explained.