Life's First Energy Source-new theory

A compound known as dark pyrophosphite could have been a source of energy that allowed the first life on Earth to form, scientists say now.

From the smallest bacteria in the human body complex, all living things require a molecule called ATP-transport energy to survive. Often compared to a "rechargeable battery," ATP chemical energy stored in a form that can be used by organic matter.

"You need enzymes to produce ATP, and ATP you need to make enzymes," said researcher Terence Kee, University of Leeds in England. "The question is: Where does the power before any of these things existed? We think the answer may lie in simple molecules such as pyrophosphate, which is chemically very similar to the ATP, but has the potential to transfer energy without enzymes. "

Dark, but important

Before the theories of how life arose from chemistry only have seen a similar compound, but independent pyrophosphate was known as the predecessor to the more complex and more efficient ATP.

Phosphate has four oxygen atoms attached to a central phosphorus atom, and is present in all living cells. When the two phosphates and lose a water molecule, form pyrophosphate.

Pyrophosphite, however, rarely encountered, the chemist Robert Shapiro of New York University told LiveScience. "Even in my Google search for it, I have the query:" does not mean pyrophosphate? '"

The presence of "one or two little thorny issues" with his rival molecule [] pyrophosphate had left some questions unanswered, Kee said in a telephone interview.

The two main problems were that the pyrophosphate does not seem to be available in significant quantities in the geological record of minerals, and does not react well without catalyst (which did not exist then), according to Kee.

On the other hand, the team has found that pyrophosphite Kee would be "relatively easy to prepare from minerals that are known to exist in iron meteorites." The routes to the production of this molecule are simpler than those proposed for the pyrophosphate, Kee said.

Although similarly produced by dehydration, and similar in composition, except that it has some oxygen atoms replaced by hydrogen, pyrophosphite is rare. Only three minerals pyrophosphite exist, as opposed to "many phosphate minerals," said Kee.

The darkness of the chemical in the earth is not a sign of its irrelevance. It is very unstable in oxygen-rich environment today (ie, breaks down into other molecules quickly), but it is a superior catalyst (jump starting) for certain chemical reactions, Kee said, citing as evidence yet publish.

Lateral thinking

Altered Kee called the theory "more a process of lateral thinking that a" new concept ".

"It is strange that so little pyrophosphite and its ability to act as transfer agent of phosphorus have been known for some time, but has not been previously proposed to be important for pre-biotic" he said. "I suspect that because no one had considered the need for him or could have been pre-biotic accessible."

Interestingly, the machines that manufacture artificial DNA experiments pyrophophite regularly used in their assembly process, said Shapiro.

The researchers detail their theory pyrophosphate as an energy source of life in a recent issue of the journal Chemical Communications.

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