March 29, 2016

"One way that RNA might have first formed is with the help of minerals, such as metal hydrides."

Space.com: These minerals can serve as catalysts, helping create small organic compounds from inorganic building blocks. By Charles Q. Choi via Astrobiology Magazine

'Such minerals are found at alkaline hydrothermal vents on the seafloor. Alkaline hydrothermal vents are also home to large chimney-like structures rich in iron and sulfur. Prior studies suggested that ancient counterparts of these chimneys might have isolated and concentrated organic molecules together, spurring the origin of life on Earth.

'To see how well these chimneys support the formation of strings of RNA, researchers synthesized chimneys by slowly injecting solutions containing iron, sulfur and silicon into glass jars. Depending on the concentrations of the different chemicals used to grow these structures, the chimneys were either mounds with single hollow centers or, more often, spires and "chemical gardens" with multiple hollow tubes.

'"Being able to perform our experiments in chimney structures that looked like something one might encounter in the darker regions of Tolkien's Middle Earth gave these studies a geologic context that sparked the imagination," said study co-author Linda McGown, an analytical chemist and astrobiologist at Rensselaer Polytechnic Institute in Troy, N.Y.

'The chimneys were grown in liquids and gases resembling the oceans and atmosphere of early Earth. The liquids were acidic and enriched with iron, while the gases were rich in nitrogen and had no oxygen. The scientists then poked syringes up the chimneys to pump alkaline solutions containing a variety of chemicals into the model oceans. This simulated ancient vent fluid seeping into primordial seas.'

"RNA Oligomerization in Laboratory Analogues of Alkaline Hydrothermal Vent Systems" by Burcar Bradley T., Barge Laura M., Trail Dustin, Watson E. Bruce, Russell Michael J., and McGown Linda B. here

No comments: