Amino Acid Alphabet Soup

How did life end up selecting which amino acids in the primordial soup worked best? Image Credit: Peter Sawyer / Smithsonian Institution
For more than 3 billion years, organisms on Earth have relied on a standard set of 20 amino acids to build the proteins that carry out life’s essential actions. But did it have to be this way? There are more than 20 amino acids available in nature, and scientists have long wondered if life could have arisen based on a different set.

Researchers with the NASA Astrobiology Institute (NAI) have devised a test to try to learn if the 20 amino acids Earth’s life uses were randomly chosen, or if they were the only possible ones that...

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Source: [astrobio.net]

August 18, 2011 / Written by: Clara Moskowitz

NASA Researchers Make First Discovery of Life's Building Block in Comet

This is an artist's concept of particle hits on the aerogel collection grid. The greenish areas represent the aerogel. Hits are the light green teardrop-shaped areas. Particles are represented by dots at the tips of the teardrops. Credit: NASA/JPL

NASA scientists have discovered glycine, a fundamental building block of life, in samples of comet Wild 2 returned by NASA’s Stardust spacecraft.

“Glycine is an amino acid used by living organisms to make proteins, and this is the first time an amino acid has been found in a comet,” said Dr. Jamie Elsila of NASA’s Goddard Space Flight Center in Greenbelt, Md. “Our discovery supports the theory that some of life’s ingredients formed in space and were delivered to Earth long ago by meteorite and comet impacts.”

Elsila is the lead author of a paper...

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Source: [Link]

August 17, 2009 / Posted by: Daniella Scalice

Meteorites a Rich Source for Primordial Soup

Scientists from NAI’s Carnegie Institution of Washington Team have a new paper in Meteoritics and Planetary Science detailing their discovery of amino acids in two meteorites at concentrations ten times higher than levels previously measured in other similar meteorites. The result suggests that the early solar system was far richer in the organic building blocks of life than scientists had thought, and that fallout from space may have spiked Earth’s primordial broth. Click here to download the paper.

March 13, 2008 / Posted by: Daniella Scalice

Mineral Surfaces and Life

Robert Hazen, from NAI’s Carnegie Institution of Washington Team, published his 2005 Presidential Address to the Mineralogical Society of America in this month’s American Mineralogist. The address reviews the role of mineral surfaces on the self-assembly of lipids, the polymerization of amino acids and nucleic acids, and the selective adsorption of organic species, including chiral molecules, onto mineral surfaces.

Source: [Link]

November 20, 2006 / Posted by: Shige Abe

Amino Acids Found in Antarctic Meteorites

Researchers from NAI’s NASA Goddard Space Flight Center Team and their colleagues publish their analysis of two meteorites in the current issue of Meteoritics and Planetary Science. Their study revealed a suite of amino acids present in the meteorites that are not present in the Antarctic ice on which they were found.

Source: [Link]

June 19, 2006 / Posted by: Shige Abe