Thermodynamic Analysis of Biological Systems

Ram Devireddy

doi:10.4172/2157-7544.1000e101

Abstract

Copyright: © 2012 Ram D. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The laws of thermodynamics traditionally describe the physical quantities (energy, entropy, temperature, volume, etc) of a thermodynamic system and the relationship between heat and work. Given that these laws are universal and represent the epitome of physical sciences, it is somewhat disconcerting to note that biologists have not always had a comfortable relationship with thermodynamics! This discomfort originates in the seemingly irreconcilable differences between the physical (simple) processes described by thermodynamics and the biological (complex) processes. As we all know, thermodynamic system tend to equilibrium, which for an isolated system implies a state of maximum disorder or maximum entropy. However, almost all biological systems do not ever reach equilibrium and seem to “evolve” to states of higher order, rather than disorder. Clearly, this discrepancy can be explained by simply noting that biological (living) systems are not isolated and are not in equilibrium with their surroundings. But this only explains why biological systems can be ordered but it does not explain how they came to be so. Of all the innumerable processes that increase entropy in the universe why does nature choose to create order in a few of its subsystems? Simply, put why does life create order out of disorder?

Highlights

The laws of thermodynamics traditionally describe the physical quantities of a thermodynamic system and the relationship between heat and work. Given that these laws are universal and represent the epitome of physical sciences, it is somewhat disconcerting to note that biologists have not always had a comfortable relationship with thermodynamics! This discomfort originates in the seemingly irreconcilable differences between the physical processes described by thermodynamics and the biological processes
Biological systems are non-equilibrium systems, equilibrium thermodynamics has been extensively utilized by biochemists
In the well accepted reductionistic approach, biologists have isolated specific processes and studied them in vitro under equilibrium conditions. This approach has two advantages: one the experimental measurements are much easier under equilibrium conditions and two the resulting experimental data can be analyzed using well established equilibrium thermodynamic laws

Summary

Introduction

The laws of thermodynamics traditionally describe the physical quantities (energy, entropy, temperature, volume, etc) of a thermodynamic system and the relationship between heat and work. Ram Devireddy* Department of Mechanical Engineering, Louisiana State University,Baton Rouge, LA 70803 USA This discomfort originates in the seemingly irreconcilable differences between the physical (simple) processes described by thermodynamics and the biological (complex) processes.

Results

Conclusion