Simplified analysis in living systems

The analysis of real biological systems may be introduced in idealized simplifications using the principles of physics, chemistry, biology, thermodynamics, and kinetics. The following examples are the simple application of these principles in describing some biological processes. 

Example 11.1 Cell electric potentials In living systems, ions in the intracellular phase and the extracellular phase produce a potential difference of about 80 mV between the two phases. The intracellular phase potential is negative (Garby and Larsen, 1995). Determine the difference in electrical potential energy per mole positive monovalent ion, e.g., Na+, between the two phases. 

Electric potential differences can exist in living systems. Changes in electrical potential energy are produced by ions in solutions whose electric potentials change across cell membranes. The potential energy per mole species at the potential t(/ is obtained from 

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Both experimental and molecular simulation studies of freezing and melting in porous materials suffer from several difficulties [1]. Difficulties in the experiments include the lack of well-characterized porous materials, difficulty in identifying the nature of the adsorbed phases, and long-lived metastable states. In the simulations, large systems and finite size scaling analysis may be needed to feel confidence in the results, and models of the porous materials may be over-simplified. The somewhat complementary nature of the difficulties in experiment and simulation make it profitable to use both approaches in a combined study. We have therefore adopted such a strategy in our recent work in this area [2-7]. 

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