Thermodynamics and Transport Systems 



Introduction to Part E 



Thermodynamics and statistical mechanics are major 

 branches of physics and physical chemistry. They 

 emphasize the application of the concept of energy and its 

 conservation law; these have proved extremely fruitful in 

 modern physics as well as in classical physics and physical 

 chemistry. Therefore, it is quite appropriate that the 

 application of thermodynamics should be a basic part of 

 biophysics. 



The concepts of chemical thermodynamics which are 

 important for biophysics are introduced in the first chapter 

 in this section. These ideas are applied in two succeeding 

 chapters to enzyme reactions and to the diffusion of mole- 

 cules through fluids and their transport through mem- 

 branes. The preceding ideas are used in the next chapter 

 to develop molecular models to explain the nature of the 

 action potentials in nerves. In the last chapter in this 

 section, information theory is introduced; its relationship 

 to thermodynamics and kinetic theory is emphasized. 



Thermodynamics is a part of physics and is described 

 best in the language of physics, namely mathematics. All 

 the chapters in this section could be called mathematical 

 biophysics (as could also parts of several other chapters). 

 It is important that the mathematical developments be 

 related to experiments or else they become nonsense. In 

 Part E, the experimental applications are outlined, but 

 the mathematical analyses are granted a greater allocation 

 of space. It is the author's belief that the approach taken 

 in these chapters will increasingly become typical of all of 

 biophysical research. 



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