Science News Archive

X-ray-ted Molecular Movies

Scientists have found a way to see molecules in motion, providing us with new insights into the way complex chemistry takes place. Zurich University's Peter Hamm and his team have used a technique called infra-red spectroscopy to track the movements of individual chemical groups in a larger molecule. The discovery is important because until now we've only been able to gain individual snapshots of what molecules look like, frozen in time, by shining x-rays through solid crystals of them. But the atoms in molecules are more like beads connected to each other by springs, and they bounce about continuously. Indeed it's these movements that enable nature's catalysts, called enzymes, to do the jobs they do, powering our metabolism. In the new technique the researchers glued down one end of a molecule and then shone infrared light at it from two directions. Because the bonds linking different chemical groups absorb infrared energy in a highly specific way it's possible to track, incredibly quickly, how these groups are moving around. At the moment the team have only worked with very simple molecules but it should be possible to scale up the process to tackle much bigger beasts. "We can use chemical isotopes placed at very specific positions in a molecule to shift the infra-red signal by a known degree and this will enable us to study more complex structures", Peter Hamm suggests.

26th Nov 2006