Simple Transport Processes

Abstract

In this chapter, we discuss simple transport processes like heat transport and diffusion in an external electric field. We discuss the fluxes of mass, energy, and entropy and their dependence on the gradients of temperature, concentration, and electrostatic potential. We derive the Nernst–Planck equation for the diffusion flux and a generalized diffusion equation for the concentration.

Problems

11.1

Synthesis of ATP from ADP

In mitochondrial membranes, ATP is synthesized according to

$$ {\text {ADP}+\text {POH}+\text {2H}}_{out}^{+}\rightleftharpoons {\text {ATP}+\text {H}}_{2}{\text {O}+\text {2H}}_{in}^{+} $$

where (in) and (out) refer to inside and outside of the mitochondrial membrane.

Express the equilibrium constant K as a function of the potential difference

$$ \varPhi _{in}-\varPhi _{out} $$

and the proton concentration ratio

$$ c(H_{in}^{+})/c(H_{out}^{+}). $$