A meteorite, which crashed into Australia 40 years ago, is telling researchers new things about how life may have started on Earth, and how that almost universal protein left-handedness came to be.
For more than 150 years, scientists have known that the most basic building blocks of life - chains of amino acid molecules and the proteins they form - almost always have the unusual characteristic of being overwhelmingly “left-handed.”
The molecules, of course, have no hands, but they are almost all asymmetrical in a way that parallels left-handedness.
This observation, first made in the 1800s by French chemist Louis Pasteur, is taught to introductory organic chemistry students - until recently with the caveat that nobody knew how this came to be.
But research into the question has picked up in recent years, focusing on a 200-pound chunk of rock found 40 years ago in Murchison, Australia. A meteorite that broke off an asteroid long ago, it brought to Earth a rich collection of carbon-based material from far away in the solar system. According to a report in Washington Post, while the Murchison meteorite does not have any once-living material, it is telling researchers new things about how life may have started on Earth, and how that almost universal protein left-handedness came to be.
The answer they believe they have found is that 3 billion to 4 billion years ago, before life on Earth began, similar meteorites crashed regularly into the planet - delivering the amino acids that would later be incorporated into all living things. - phenomica
The back up Blog of the real Xenophilius Lovegood, a slightly mad scientist.
Tuesday, October 7, 2008
“Space rock” reveals life’s origins
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