Researchers at The Scripps Research Institute (TSRI) in the US hypothesised that a chemical reaction called phosphorylation may have been crucial for the assembly of three key ingredients in early life forms.
These ingredients are short strands of nucleotides to store genetic information, short chains of amino acids (peptides) to do the main work of cells, and lipids to form encapsulating structures such as cell walls.
No one has ever found a phosphorylating agent that was plausibly present on early Earth and could have produced these three classes of molecules side-by-side under the same realistic conditions, researchers said.
TSRI chemists have now identified just such a compound: diamidophosphate (DAP).
“We suggest a phosphorylation chemistry that could have given rise, all in the same place, to oligonucleotides, oligopeptides, and the cell-like structures to enclose them,” said Ramanarayanan Krishnamurthy, associate professor of chemistry at TSRI.
“That in turn would have allowed other chemistries that were not possible before, potentially leading to the first simple, cell-based living entities,” Krishnamurthy said.
The study, published in the journal Nature Chemistry, is part of an ongoing effort by scientists around the world to find plausible routes for the epic journey from pre- biological chemistry to cell-based biochemistry.
Other researchers have described chemical reactions that might have enabled the phosphorylation of pre-biological molecules on the early Earth.
However, these scenarios have involved different phosphorylating agents for different types of molecule, as well as different and often uncommon reaction environments.
“It has been hard to imagine how these very different processes could have combined in the same place to yield the first primitive life forms,” said Krishnamurthy.
Researchers, including Megha Karki, a postdoctoral research associate at TSRI, showed first that DAP could phosphorylate each of the four nucleoside building blocks of RNA in water or a paste-like state under a wide range of temperatures and other conditions.
With the addition of the catalyst imidazole, a simple organic compound that was itself plausibly present on the early Earth, DAP’s activity also led to the appearance of short, RNA-like chains of these phosphorylated building blocks.
“With DAP and water and these mild conditions, you can get these three important classes of pre-biological molecules to come together and be transformed, creating the opportunity for them to interact together,” Krishnamurthy added.
thanks: Deccan chronicle.
dedicated by: Kavignar Thanigai.
India’s only live volcano in the Andaman and Nicobar Islands which had started showing activity in the year 1991 after being dormant for over 150 years has once again started spewing ash, the researchers at Goa based National Institute of Oceanography (NIO) said today.
“The only live volcano in the Andaman and Nicobar islands is erupting once again. The Barren Island volcano, located 140-km north-east of Port Blair, dormant for more than 150 years started erupting in 1991 and has since then shown intermittent ctivity,” CSIR-NIO said in a statement here.
A team of scientists led by Abhay Mudholkar, from CSIR-National Institute of Oceanography (CSIR-NIO) in Goa reported that the volcano is active and spewing smoke and lava once again.
“On the afternoon of January 23, 2017, the scientific team on board CSIR-NIO’s research ship R V Sindhu Sankalp were busy collecting sea floor samples in the Andaman Basin near the Barren volcano when it suddenly started spewing ash,” the NIO has said.
“The team moved about one mile from the volcano and began closely observing it. It was erupting in small episodes lasting about five to ten minutes,” said the release.
During the daytime only ash clouds were observed.
However, after sundown, the team observed red lava fountains spewing from the crater into the atmosphere and hot lava flows streaming down the slopes of the volcano, it said.
NIO has said the volcano was revisited in the early hours of January 26, 2017 again during the second leg of the cruise led by B Nagender Nath, it said, adding the team witnessed the continuation of spurts of blasts and smoke.
“They have sampled the sediments and water in the vicinity of the volcano and recovered coal-like black pyroclastic material representing proximal volcanic ejecta.
Clouds were seen at the crater mouth where the smoke was bellowing out in otherwise clear sky,” the researchers said.