Life's first energy source discovered
Scientists think a little-known compound called pyrophosphite could have allowed first life on Earth to form.
Mon, Jun 14, 2010 at 11:00 PM
Life on Earth requires an energy-transporting molecule called ATP to survive. And as experts point out, you need enzymes to make ATP and ATP to make enzymes. But what came before ATP, when life on Earth was devoid of ATP, enzymes, and everything that comes afterward? LiveScience reports that the energy source before all energy sources has been discovered. And it is an obscure compound called pyrophosphite.
ATP is sometimes compared to a "rechargeable battery," as it stores chemical energy that can be used by organic matter. Terence Kee is a researcher at the University of Leeds in England. As he told LiveScience, "You need enzymes to make ATP, and you need ATP to make enzymes. The question is: Where did energy come from before either of these two things existed? We think that the answer may lie in simple molecules, such as pyrophosphate, which is chemically very similar to ATP, but has the potential to transfer energy without enzymes."
Previously, scientists thought that life emerging from “mere chemistry” came from a similar compound called pyrophosphate. But there were problems with this theory – pyrophosphate wasn’t abundantly present in early Earth, and it doesn't react well without catalysts. This is a problem as catalysts weren’t around during the dawn of time. But pyrophosphite could be made from the chemicals that exist in iron meteorites. And meteorites were certainly hitting the Earth in its earliest years.
The fact that pyrophosphite is so rare on modern Earth does not worry scientists, as it is considered highly unstable in today's oxygen-rich environment. But as Kee tells LiveScience, this new idea is more lateral than new. According to Kee, "It is a little strange that pyrophosphite and its ability to act as a phosphorus-transfer agent have been known for some time but it has not been proposed previously as being of any pre-biotic significance…I suspect because no one had considered the need for it or that it may have been accessible pre-biotically." Hopes are that this theory may provide some long-sought answers to the origins of life.
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