UAB scientists discover the origin of a mysterious physical force

[C1ay]

Ever since the 1970s, scientists have been trying to establish the cause of a repulsive force occurring between different electrostatically charged molecules, such as DNA and other biomolecules, when they are very close to each other in aqueous media. This force became know as hydration force.

 

lefthttp://www.hypography.com/gallery/files/9/9/8/hydration_force_thumb.jpg[/img]Jordi Faraudo, a researcher for the Department of Physics at the Universitat Autònoma de Barcelona, and Fernando Bresme of the Department of Chemistry at Imperial College London have studied this mysterious force in detail and have discovered where its origins lie.

 

In the same way that a flag flutters in the direction the wind is blowing, at a microscopic level water molecules are gently attracted towards the direction in which an electric field is pointing. However, when the water is in contact with surfaces that create small electric fields, such as chemical compounds like those found in many detergents, this is no longer the case: the water molecules have a remarkable capacity to organise themselves into complex structures that are strongly orientated in such a way as to cancel out the electric field, and on some occasions, to reverse it. This abnormal behaviour was discovered by the same researchers and published in Physical Review Letters in April 2004.

 

The scientists have now discovered that this strange property is responsible for the hydration force that acts when water is surrounded by certain types of electrostatically charged molecules, such as DNA and some biological compounds, and when thin films form in detergents. The discovery has been published in today's edition of Physical Review Letters.

 

Water is the solvent in which most physical, chemical and biological processes take place. Therefore, it is essential to understand the nature of interactions between molecules dissolved in water in order to understand many of these processes. Two of the most important of these processes are the adherence of substances to cell membranes and the withdrawal of proteins. Both of these are fundamental in biomedical research, since a substantial part of the process of designing new drugs is based on understanding how substances penetrate cell membranes to enter cells. These drugs are often proteins designed to prevent or strengthen the action of other substances. In these cases, accurately identifying the protein folding is essential, since the form these proteins take on when they fold influences how effectively they are able to act.

 

Fully understanding the properties of this force that occurs when molecules surrounded by water adhere to each other is also useful in the chemical industry, particularly when involving mechanisms in which colloidal suspensions must be stabilised, such as the mechanisms used to produce paints, cosmetics and food products such as yoghurt and mayonnaise.

 

Source: Universitat Autonoma de Barcelona

[Tormod]

This is really interesting stuff. But are they talking about another fundamental force or just another application of one of them?

[C1ay]

This is really interesting stuff. But are they talking about another fundamental force or just another application of one of them?

 

It looks to me like the mysterious hydration force is really the electrical force acting at the molecular level.

[Turtle]

The article says, "Two of the most important of these processes are the adherence of substances to cell membranes and the withdrawal of proteins. Both of these are fundamental in biomedical research, since a substantial part of the process of designing new drugs is based on understanding how substances penetrate cell membranes to enter cells. "

___Some years ago in Scientic American I read an article about the structures in cells called 'micro tubules'. Contrary to the idea of protoplasm being some homogenous aqueous gell, at least 3 different kinds of micro tubules give the cell shape & support, as well as conducting chemicals to & from the memebrane & to & from internal structures.

___In spite of the fact this is relatively old news, I never see micro tubules mentioned in current discussions of cells. What gives? :Alien: