Water biophysical role

As multicellular life forms reached a sufficient degree of complexity, they improved their physical separation from the water medium, allowing migration to land and continued evolution in novel environments. In terrestrial plants and animals, water is no longer both external and internal, but solely the internal milieu, the milieu interieur, in constant flux with the environment yet carefully separated from it Such, in a nutshell, is the biophysical role of water as a medium. 

Three theory papers are also included. Determinants of the Polyproline II Helix from Modeling Studies by Creamer and Campbell reexamines and extends an earlier hypothesis about Pn and its determinants. Hydration Theory for Molecular Biophysics by Paulaitis and Pratt discusses the crucial role of water in both folded and unfolded proteins. Unfolded State of Peptides by Daura et al. focuses on the unfolded state of peptides studied primarily by molecular dynamics. 

It has become Increasingly obvious to us that regulation of water balance In Insects Is one of the keys to the success of these animals In their adaptation to such a wide variety of habitats. The complexities Involved In undertaking studies of such systems may require expansion of our Interdisciplinary approach so as to Include such diverse fields as biophysics, ecology, and cell biology. The subject Is a fascinating one, perhaps all the more so due to Its complexity, and promises to open up new areas In which Interdisciplinary research will play a role. 

The reasons, therefore, for the excellent barrier properties of the skin are the tortuous route and that a penetrant has to cross sequentially a large number of rigid bilayers. The role of the lipids in topical delivery, how they control water transfer through the skin, and how biophysical techniques have been used to examine them have been reviewed [18-20]. 

Two points should be added to these conclusions. First, if the role of H-bonds appears so fundamental in biophysics and biochemistry that H-bonds may be declared the bonds of life , mainly thanks to the presence of H2O molecules in aU biomedia and to the fundamental role they play there, their action is not limited to these media. The HjO molecule being ubiquitous, thanks to its exceptional possibilities to establish H-bonds, H-bonds are also often encountered in chemistry, where such terms as H-bonded solvents, hydrophilic or hydrophobic groups or molecules are currently encountered and well taken into account, even if a more precise understanding of the role that these HjO molecules play is often needed. They are, also often encountered in physics where H2O molecules are also currently met. Physicists, however, are less aware of their fundamental role. We have seen that the dynamics of HjO molecules in liquid water is yet not understood at all. It is studied by recent time-resolved nonlinear IR methods that are stiU the domain of physicists and also by theoretical methods of molecular dynamics (MD) that have up to now not succeeded in incorporating the directionality of H-bonds in the huge H-bond network of liquid water and consequently the fundamental role rapid rotations (librations) of these very small H2O molecules play. In another... 

Clegg, J. S. (1982). Alternative views on the role of water in cell function. In Biophysics of Water (Franks, F. Mathias. S., eds.), pp. 365-383, John Wiley Sons, New York. 

Interfaces play a central role in electrochemistry, biophysics, drug delivery, and surfactant science. The study of interfacial phenomena at the molecular or atomic level is an active field with significant contributions from both experiment [1,2] and theory [3]. In this article, we will present some initial results concerning the structure and electrostatics of the surfactant-water interface. In particular, we will focus on the sodium oc-tanoate-water system in the lyotropic liquid crystalline mesophase (E). In this phase the surfactant forms very long micelles which pack in a hexagonal pattern. This is a good... 

Biophysics applications have played and will continue to play a large role in medicine and health care, but future biophysicists may be environmental scientists. Biophysics is providing ways to improve the environment. For example, scientists are modifying microorganisms so that they produce electricity and biofuels that may lessen the need for fossil fuels. They are also using microorganisms to clean polluted water. As biophysics research continues, its applications are likely to cover an even broader range. 

Cayley, S. and Record, M.T., Roles of cytoplasmic osmolytes, water and crowding in the response of Escherichia coli to osmotic stress biophysical basis of osmoprotection by glycine betaine. Biochemistry, 42,12595, 2003. 

---