It's a chicken-and-the-egg puzzle: How could the basic biochemicals like amino acids and nucleotides have come about when there were no catalysts, like proteins or ribosomes, around to create them?

Now scientists propose that a third type of catalyst could have jumpstarted metabolism and life itself, deep in hydrothermal ocean vents, an article in The Biological Bulletin says.

The scientists' theory says molecular structures involving transition metal elements -- iron, copper, nickel, etc. -- and ligands -- small organic molecules -- could have catalyzed the synthesis of basic biochemicals, monomers, that acted as building blocks for more complex molecules, leading ultimately to the origin of life.

"There has been a big problem in the origin of life (theory) for the last 50 years in that you need large protein molecules to be catalysts to make monomers, but you need monomers to make the catalysts," Harold Morowitz of George Mason University in Virginia says.

However, he suggests, "You can start out with these small metal-ligand catalysts, and they'll build up the monomers that can be used to make" the large protein catalysts.

Morowitz and his colleagues propose that simple transition metal-ligand complexes in hydrothermal ocean vents catalyzed reactions that gave rise to more complex molecules. These complex molecules then acted as ligands in increasingly efficient catalysts. Gradually, the basic molecular ingredients of metabolism accumulated and self-organized into chemical reactions laying the foundation for life.

"The idea has emerged from a study of the periodic table," Morowitz says. "We strongly feel that unless you're able to see how life comes about in some formal chemical way, you're never really going to solve the problem."

del.icio.us	Digg	Reddit
YahooMyWeb	Google	Facebook

Lands Beyond Beyond - extra solar planets - news and science
Life Beyond Earth

Memory Foam Mattress Review

SPACE MEDIA NETWORK PROMOTIONS Solar Energy Solutions Tempur-Pedic Mattress Comparison ... Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

A Dusty, Cloudy Exoplanet
Moffett Field CA (SPX) Sep 02, 2010
Astronomers at the University of Hawaii have measured the temperature of a young gas-giant planet around another star using the W. M. Keck Observatory, and the results are puzzling. They have found that its atmosphere is unlike that of any previously studied extrasolar planet. By obtaining a spectrum of its emitted light, the astronomers determined the temperature of the planet. As a resul ... read more