Chapter 18, Problem 109AP

Interpretation Introduction

Interpretation:

The Gibbs free energy change required to secrete a mole of ${\text{H}}^{+}$ ions from blood plasma is to be determined with given pH of gastric juice and blood plasma.

Concept introduction:

All the energy available with the system, which is utilized in doing useful work, is called Gibbs free energy.

The standard free energy of formation is defined as the free energy change that occurs when one mole of the compound is combined from its constituent elements, each in their standard states.

The relation between free energy change and standard free energy change is as follows:

$\Delta G=\Delta G^{\text{o}}+\text{R}T\ln Q$

Here, $\Delta G$ is free energy change, $\Delta G^o$ is standard free energy change, $Q$ is the reaction quotient, $\text{R}$ is the gas constant, and $T$ is the temperature.

At equilibrium, the above equation is reduced to the expression: $\Delta G^{\text{o}}\text{=}-\text{R }T\text{lnK }$

The overall free energy change for the transport of 3 moles of glucose into the cell is calculated as

$\text{Overall}\Delta G=\text{Moles}\text{of}\text{glucose}\times \Delta G$