Are the main building blocks of life from distant space?

Churyumov-Gerasimenko. Credit: ESA / Rosetta / NAVCAM

All living things need cells and energy to replicate. Without these basic elements, living organisms on Earth could not reproduce and simply would not exist.

Little was known about a key component of the building blocks, phosphates, until now. Researchers at the University of Hawaii at Manoa, in collaboration with French and Taiwanese colleagues, bring new compelling evidence that this component of life has been generated in space by a first billion dollars. Years by meteorites or comets. The phosphorus compounds were then incorporated into biomolecules found in cells in living beings on Earth.

Advanced research is described in "An Interstellar Synthesis of Phosphorus Oxo Acids," written by Andrew Turner, currently a student at Pikeville University, and UH Manoa Chemistry Professor Ralf Kaiser, in the September issue of Nature Communications.

According to the study, phosphates and diphosphoric acid are two essential elements for these building blocks in molecular biology. They are the main constituents of the chromosomes, carriers of the genetic information in which the DNA is located. With phospholipids in cell membranes and adenosine triphosphate, which serve as energetic vectors in cells, they form a self-replicating material present in all living organisms.

In an ultra-vacuum chamber cooled to 5 K (-450 ° F) in the WM Keck Research Laboratory in Astrochemistry at UH Manoa, the Hawaii team reproduced interstellar ice grains coated with carbon and water, ubiquitous in cold molecular clouds, and phosphine. When they are exposed to ionizing radiation in the form of high energy electrons to simulate cosmic rays in the space, several phosphorus oxoacids such as phosphoric acid and l & # 39; diphosphoric acid were synthesized via unbalanced reactions.

"On Earth, phosphine is deadly to living things," said Turner, lead author. "But in the interstellar medium, exotic phosphine chemistry can promote rare chemical reaction pathways to initiate the formation of biorixed molecules such as oxoacids of phosphorus, which could eventually trigger the molecular evolution of life as we do. know.

Kaiser added: "The phosphorus oxoacids detected in our experiments by a combination of sophisticated analyzes involving lasers, coupled with mass spectrometers and gas chromatographs, could also have formed in ice creams such as Kaiser says that these techniques can also be used to detect minute amounts of explosives and drugs.

"Since comets at least partially contain the remains of the protoplanetary disk material that formed our solar system, these compounds could go back to the interstellar medium wherever a sufficient amount of phosphine in interstellar ice is available," said Cornelia Meinert of the University of Nice. (La France).

Upon delivery to Earth by meteorites or comets, these phosphorus oxoacids may be available for the prebiotic phosphorus chemistry of the Earth. Therefore, an understanding of the easy synthesis of these oxoacids is essential to unravel the origin of water soluble prebiotic phosphorus compounds and how they might have been incorporated into organisms not only on Earth but potentially in our universe too.

Turner and Kaiser worked with Meinert and Agnes Chang of Dong Hwa National University (Taiwan) on this project.