Posted by Witty in chat:

Key ingredients for life on earth found in Australian meteorite

Washington: A fresh examination of meteorites that landed in Australia, the US and Canada is bolstering the notion that similar extraterrestrial objects may have delivered chemical ingredients vital for the advent of life.

Scientists previously detected on these meteorites three of the five chemical components needed to form DNA, the molecule that carries genetic instructions in living organisms, and RNA, the molecule crucial for controlling the actions of genes. Researchers said on Tuesday they have now identified the final two after fine-tuning the way they analysed the meteorites.

Unlike in previous work, the methods used this time were more sensitive and did not use strong acids or hot liquid to extract the five components, known as nucleobases, according to astrochemist Yasuhiro Oba of Hokkaido University’s Institute of Low Temperature Science in Japan, lead author of the study published in the journal Nature Communications.

The Rev Dodgson said:

Posted by Witty in chat:

Key ingredients for life on earth found in Australian meteorite

Washington: A fresh examination of meteorites that landed in Australia, the US and Canada is bolstering the notion that similar extraterrestrial objects may have delivered chemical ingredients vital for the advent of life.

Scientists previously detected on these meteorites three of the five chemical components needed to form DNA, the molecule that carries genetic instructions in living organisms, and RNA, the molecule crucial for controlling the actions of genes. Researchers said on Tuesday they have now identified the final two after fine-tuning the way they analysed the meteorites.

Unlike in previous work, the methods used this time were more sensitive and did not use strong acids or hot liquid to extract the five components, known as nucleobases, according to astrochemist Yasuhiro Oba of Hokkaido University’s Institute of Low Temperature Science in Japan, lead author of the study published in the journal Nature Communications.

https://www.nature.com/articles/s41467-022-29612-x..

Identifying the wide diversity of extraterrestrial purine and pyrimidine nucleobases in carbonaceous meteorites.

In addition to previously detected purine nucleobases in meteorites such as guanine and adenine, we identify various pyrimidine nucleobases such as cytosine, uracil, and thymine, and their structural isomers such as isocytosine, imidazole-4-carboxylic acid, and 6-methyluracil.

some of these derivatives could have been generated by photochemical reactions

we analyze nucleobases extracted from the Murchison, Murray, and Tagish Lake meteorites using high-performance liquid chromatography coupled with electrospray ionization high-resolution mass spectrometry (HPLC/ESI-HRMS) to examine the molecular profiles and determine the abundance of N-containing heterocyclic molecules

There has always been the question in my mind as to how important nucleobases like these are to the origin of life.

They could be essential – or irrelevant.

My thoughts currently are:

Start with small amino-acid polymers.
With iron catalysis of beta-sheet proteins these slowly select for larger amino acids, until these beta-sheet proteins start acting as enzymes.

Lipid bilayers of bacteria size have been observed in repeats of the Miller-Urey type experiment.

These lipid bilayers attract proteins.

The first fuel source of mayor importance is monosaccharides.
Some protolife learns to polymerise these into long chain polysaccharides

Then phosphates are discovered, as products of weathering of apatite rock. Phosphates are first used as an energy source, attached to monosaccharides.

Only then do nucleobases become important, a long way down the evolutionary chain, as they attach to make AMP.

RNA comes into play first as an energy storage for phosphates. Only later as transfer RNA for polymerisation of proteins.

https://www.nature.com/articles/s41467-022-29612-x

Link

Identifying the wide diversity of extraterrestrial purine and
pyrimidine nucleobases in carbonaceous meteorites