Chemical Evolution - Progenitors Of The Living World

[hazelm]

This one is going to need some translation - for me, at least.  RNA probably the first informational molecule.  And, again, we read about the need for wet and dry conditions to drive the prebiotic synthesis of the RNA molecules.  Q:  RNA molecules may be the first "informational molecule" but does that make it the first start of life?

[exchemist]

This one is going to need some translation - for me, at least.  RNA probably the first informational molecule.  And, again, we read about the need for wet and dry conditions to drive the prebiotic synthesis of the RNA molecules.  Q:  RNA molecules may be the first "informational molecule" but does that make it the first start of life?

I am not sure what it really meant by "the first informational molecule". That strikes me as a bold claim requiring justification. I should have thought that RNA would be far too complex to be the first molecule that enabled other molecules to be copied, which is the process that had to start at some point in abiogenesis. The first self-replicating biochemical systems may have relied on far simpler things, yet to be discovered.

 

But have you a reference for this comment? Reading the context might help a bit.   

[hazelm]

I am not sure what it really meant by "the first informational molecule". That strikes me as a bold claim requiring justification. I should have thought that RNA would be far too complex to be the first molecule that enabled other molecules to be copied, which is the process that had to start at some point in abiogenesis. The first self-replicating biochemical systems may have relied on far simpler things, yet to be discovered.

 

But have you a reference for this comment? Reading the context might help a bit.   

Oh, I forgot to post that.  Sorry.  Give me a minute.    Let me test this and see if it is right.  If not, I'll be back with correct URL.

 

Yes, this is it.

 

https://www.sciencedaily.com/releases/2018/01/180117131129.htm?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+sciencedaily%2Ftop_news%2Ftop_science+%28ScienceDaily%3A+Top+Science+News%29

Edited January 18, 2018 by hazelm

[exchemist]

Oh, I forgot to post that.  Sorry.  Give me a minute.    Let me test this and see if it is right.  If not, I'll be back with correct URL.

 

Yes, this is it.

 

https://www.sciencedaily.com/releases/2018/01/180117131129.htm?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+sciencedaily%2Ftop_news%2Ftop_science+%28ScienceDaily%3A+Top+Science+News%29

Aha. Thanks. It doesn't seem as if they get into justifying the claim that RNA was the first "informational molecule", but I think they are implicitly referring to the "RNA world" hypothesis. https://en.wikipedia.org/wiki/RNA_world

 

What they have done is show that the building blocks of RNA, which are called "nucleosides" can be synthesised from fairly simple organic molecules in alternating wet and dry conditions and in the presence of Fe and Ni as catalysts. Which is interesting.

 

I had to look up what these nucleosides are: a molecule in 2 parts, a ribose (5 carbon simple sugar) linked to a nitrogenous base (thymine, adenine, guanine etc). In RNA, nucleosides link together in long chains, the link being a phosphate group that joins to one of the -OH groups on each ribose.  

 

The Wiki article on RNA world does say that there may well have been some simpler stage before it, perhaps with just a few of these units or with something even simpler. But, like the article on phosphorylation you provided earlier, this is another possible step on the road to understanding abiogenesis. 

[hazelm]

Aha. Thanks. It doesn't seem as if they get into justifying the claim that RNA was the first "informational molecule", but I think they are implicitly referring to the "RNA world" hypothesis. https://en.wikipedia.org/wiki/RNA_world

 

What they have done is show that the building blocks of RNA, which are called "nucleosides" can be synthesised from fairly simple organic molecules in alternating wet and dry conditions and in the presence of Fe and Ni as catalysts. Which is interesting.

 

I had to look up what these nucleosides are: a molecule in 2 parts, a ribose (5 carbon simple sugar) linked to a nitrogenous base (thymine, adenine, guanine etc). In RNA, nucleosides link together in long chains, the link being a phosphate group that joins to one of the -OH groups on each ribose.  

 

The Wiki article on RNA world does say that there may well have been some simpler stage before it, perhaps with just a few of these units or with something even simpler. But, like the article on phosphorylation you provided earlier, this is another possible step on the road to understanding abiogenesis. 

Nucleosides!  That was one thing that stopped me in the article.  I thought the word was nucleotides.  I have a paper somewhere about (I am sure) nucleotides.  Must dig that out.

 

I'll read the Wiki article.  Thanks for that.  My problem is them making any molecules as the "first" of anything.  But they do say it is the first "information" molecule.  Can I substitute "informative"?  In other words, I am asking do they mean it's the earliest they can go back to and get some accurate information about the possible basics of life?  Poor example but something like taking a cake apart and learning what ingredients were used. 

 

We are getting a collection of possibilities here anyway.  Thanks for your thoughts.

[exchemist]

Nucleosides!  That was one thing that stopped me in the article.  I thought the word was nucleotides.  I have a paper somewhere about (I am sure) nucleotides.  Must dig that out.

 

I'll read the Wiki article.  Thanks for that.  My problem is them making any molecules as the "first" of anything.  But they do say it is the first "information" molecule.  Can I substitute "informative"?  In other words, I am asking do they mean it's the earliest they can go back to and get some accurate information about the possible basics of life?  Poor example but something like taking a cake apart and learning what ingredients were used. 

 

We are getting a collection of possibilities here anyway.  Thanks for your thoughts.

No, nucleotides are nucleosides with the phosphate group already attached. : https://en.wikipedia.org/wiki/Nucleoside

 

By "information molecule" I assume they mean a molecule with an instruction code for building other molecules, as DNA does. RNA does something similar.  So the "information" is the details of what molecules it enables to be built. 

[hazelm]

No, nucleotides are nucleosides with the phosphate group already attached. : https://en.wikipedia.org/wiki/Nucleoside

 

By "information molecule" I assume they mean a molecule with an instruction code for building other molecules, as DNA does. RNA does something similar.  So the "information" is the details of what molecules it enables to be built. 

Thanks again.