2023-12-05 10:15:04
The emergence of life on Earth from simple chemicals is one of the most exciting and at the same time most challenging topics in biochemistry and perhaps in all of science. Modern life forms can transform nutrients into all types of compounds through complex chemical networks; What’s more, they can catalyze very specific transformations using enzymes, achieving very precise control over which molecules are produced. However, enzymes did not exist before life arose.
Thus, it is likely that at an earlier time in Earth’s history there existed various non-enzymatic chemical networks that could convert nutrients in the environment into compounds that supported primitive cell-like functions.
Pentose synthesis is a prominent example of this scenario. These simple sugars, which only contain five carbon atoms, are the building blocks of RNA and other molecules essential for life as we know it.
However, the availability of pentoses during the Earth’s infancy is unclear, as these molecules are unstable.
A new study, carried out by Ruiqin Yi’s team, from the Tokyo Institute of Technology in Japan, reveals a chemical pathway compatible with the conditions prevailing on our planet before the emergence of life and by which C6 aldonates could have acted as a source of pentoses without the need for enzymes.
The new study provides key clues about the primordial biochemistry and prebiotic setting in which life emerged. (Image: NASA Goddard Space Flight Center Conceptual Image Lab. CC BY-NC-ND)
A key detail in this regard is that aldonates have been found in abundance in the famous Murchison meteorite, which fell to Earth in 1969. In contrast, the meteorite lacks the carbohydrates typical of modern biological systems. This implies that aldonates can form and accumulate in conditions like those prevailing in some places outside Earth, and the new study suggests that they could have played an important role in the entry into the scene of the first basic components of life, the antechamber of the emergence of the first form of life.
The study is titled “Carbonyl Migration in Uronates Affords a Potential Prebiotic Pathway for Pentose Production.” And it has been published in the academic journal JACS Au. (Source: NCYT from Amazings)
#discover #key #origin #life #Earth #meteorite