Sunday, August 30, 2009

More on the structure of water from SLAC via World Science

"Dance restaurant" theory of water takes shape
Aug. 14, 2009 Courtesy SLAC National Accelerator Laboratory and World Science staff

Everyone knows water -- it shapes our bodies and our planet. But de­spite this abundance, the molecular structure of water has remained a mystery. Com­pared to other liquids, water has strange properties that are still poorly understood.

Recent work at the U.S. Department of Energy’s SLAC National Accelerator Laboratory and universities in Sweden and Japan, though, is shedding new light on water’s molecular idiosyncrasies, offering insight into its odd properties.

How water molecules arrange themselves in the substance’s solid form, ice, was long ago established: the molecules form a tight “tetrahedral” lattice, with each molecule binding to four others.

Discovering the molecular arrangement in liquid water, however, is proving to be much more complex.

Nilsson and colleagues recently directed powerful X-rays at samples of liquid water. Their results suggested the textbook model of water at ordinary conditions was wrong and that, unexpectedly, two distinct structures, either very disordered or very tetrahedral, exist no matter the temperature.

In a paper published in the journal Proceedings of the National Academy of Sciences, the researchers reported the additional finding that the two types of structure are spatially separated, with the tetrahedral structures existing in "clumps" made of up to about 100 molecules surrounded by disordered regions."

The whole story is at

-- End announcement --

-- In respiration sites within cells, as molecules form one at a time or in small numbers at a time per location it seems reasonable for a  propensity for ordered tetrahedral arrangements.        -- Ralph Frost

Powered by Qumana

No comments:

Post a Comment

Leave a comment