Advances in Chirality and other problems of abiogenesis in the Origins of Life

[lee_merrill]

Homchirality is an attribute of complex life...

It's an attribute of all life: "Life exists in single-handed forms."

In fact the proposals in the article describe 'how homochirality developed over time.

They describe various approaches, but all seem inconclusive: "the problem may seem trivial at first glance, but chemists still do not understand how it happened."

The pros and cons of how and when homochirality developed is most definitely at issue here.

That's fine, but the reason I brought up the article is that you said there is no evidence that 100% homochirality is required. There is evidence, there are clear statements in the article that it is required. One section is even titled "No homochirality, no life".

Selective citations do not justify your religious agenda. The proposals for the development of homochirality developed in the pre-life evolution that led to homochirality.

So what is the best approach describing how homochirality developed?

Blessings,
Lee

[lee_merrill]

And you have yet to tell me whether the building blocks in the second article you posted were racemic.

Source: Reasons to Believe

These requirements demand that the origin of homochiral amino acids and ribose sugars must precede the origin of proteins, DNA, and RNA. That is, without preexisting large reservoirs of exclusively left-handed amino acids for each of the 19 bioactive amino acids and preexisting large reservoirs of exclusively right-handed ribose sugars, any naturalistic assembly of proteins, DNA, and RNA is ruled out. Without such reservoirs, naturalistic origin-of-life models are prohibited.

Source

© Copyright Original Source

Blessings,
Lee

[shunyadragon]

It's an attribute of all life: "Life exists in single-handed forms."

True, so what?!?!?! I believe The Lurch and I have addressed this many times. The formation of homochirality took place in the processes of abiogenesis as the the article and the Lurch previously described

They describe various approaches, but all seem inconclusive: "the problem may seem trivial at first glance, but chemists still do not understand how it happened."

'Seem' is a problem and does not reflect what the article described. ]Arguing; from ignorance is your greatest strength. All the ways chirality formed in the processes of abiogenesis in the formation of the first RNA/DNA life. The only thing inconclusive is which of the chemically' possible' ways of homochirility formed in the processes that resulted in the first RNA.

None of the references that described the possible chemical processes proposed that you need perfect homochirility for the process to become a part of the formation of the first RNA. They all describe homochirality forming over time by chemical processes described in the research.

That's fine, but the reason I brought up the article is that you said there is no evidence that 100% homochirality is required. There is evidence, there are clear statements in the article that it is required. One section is even titled "No homochirality, no life".

That is not what the article described if you read the whole article. Of course in complex life forms with RNA/DNA require homochirality, but you are neglecting the 'facts' that the article describes how homochirality can form in several different ways in pre-life abiogenesis.

So what is the best approach describing how homochirality developed?

There is no best way homochirality formed at present. The research references provided chemically valid ways homochirality can form by inorganic chemistry in the abiogenesis pre=life prior to the formation RNA/DNA life.

You are most definitely misrepresenting the article as a whole. and selectively cite only what justifies your agenda.

[shunyadragon]

And you have yet to tell me whether the building blocks in the second article you posted were racemic.



Blessings,
Lee

I already determined that your source is not a reliable scientific source and has a religious agenda not accepted by the sciences of evolution and abiogenesis. Simple response is in inorganic nature most organic chemical are originally mostly racemic like those that arrived on asteroids in huge amounts during the Hadean Eon of earth's history. . There is evidence as cited that organics from asteroids are not totally racemic. The processes of abiogenesis evolve homochirality selectively as likely by one of the methods in the source you cited as preferencal survival advantage for the complex life forms to evolve. Those that did not have homochirality did not survive.

There is some indication that the early primitive forms of prokaryotes like archaea and bacteria had homochirality and imparted homochirality on the other first primitive life forms as the origin of the nucleus and the other organelles of cells that the early bacteria invaded.

I only respond to scientific articles like you cited and dishonestly misrepresented.

[shunyadragon]

This article goes into some detail concerning the experimental studies concerning how chirality formed during abiogenesis.

Source: cshperspectives.cshlp.org/content/11/3/a032540.abstract

The Origin of Biological Homochirality
Donna G. Blackmond
+Author Affiliations

Department of Chemistry, The Scripps Research Institute, La Jolla, California 92037
Correspondence: [email protected]
SUMMARY
The fact that sugars, amino acids, and the biological polymers they construct exist exclusively in one of two possible mirror-image forms has fascinated scientists and laymen alike for more than a century. Yet, it was only in the late 20th century that experimental studies began to probe how biological homochirality, a signature of life, arose from a prebiotic world that presumably contained equal amounts of both mirror-image forms of these molecules. This review discusses experimental studies aimed at understanding how chemical reactions, physical processes, or a combination of both may provide prebiotically relevant mechanisms for the enrichment of one form of a chiral molecule over the other to allow for the emergence of biological homochirality.

© Copyright Original Source

[lee_merrill]

True, so what?!?!?! I believe The Lurch and I have addressed this many times. The formation of homochirality took place in the processes of abiogenesis as the the article and the Lurch previously described.

Where has TheLurch described this? And in fact, the article only surveys attempts that have been unsuccessful at providing a way homochirality could have come about: "the problem may seem trivial at first glance, but chemists still do not understand how it happened."

None of the references that described the possible chemical processes proposed that you need perfect homochirility for the process to become a part of the formation of the first RNA.

The reference above states very explicitly that perfect homochirality is required. One section is even titled "No homochirality, no life".

There is no best way homochirality formed at present.

You can't tell me the best way? I only ask you to tell me the best way for homochirality to form, and let's discuss this.

Simple response is in inorganic nature most organic chemical are originally mostly racemic like those that arrived on asteroids in huge amounts during the Hadean Eon of earth's history.

Alright then, so they need to address the chirality problem. But how is it that organic chemicals arrived in huge amounts? I need a reference...

Blessings,
Lee

[lee_merrill]

This article goes into some detail concerning the experimental studies concerning how chirality formed during abiogenesis.

Source: cshperspectives.cshlp.org/content/11/3/a032540.abstract

This review discusses experimental studies aimed at understanding how chemical reactions, physical processes, or a combination of both may provide prebiotically relevant mechanisms for the enrichment of one form of a chiral molecule over the other to allow for the emergence of biological homochirality.

© Copyright Original Source

"May" and "might" are evidence of tenativeness, not so conclusive as showing "how chirality formed".

Blessings,
Lee

Blessings,
Lee

[shunyadragon]

"May" and "might" are evidence of tenativeness, not so conclusive as showing "how chirality formed".

Blessings,
Lee

Blessings,
Lee

Misquoting out of context.

[shunyadragon]

Where has The Lurch described this? And in fact, the article only surveys attempts that have been unsuccessful at providing a way homochirality could have come about: "the problem may seem trivial at first glance, but chemists still do not understand how it happened."

The Lurch repeatedly described that pure homochirality is not required in pre-life forms of abiogenesis, and the chemical processes of abiogenesis are what lead to the complex RNA/DNA life where homochirality evolved and the early pre-life forms do not require perfect homochirality.

No where in the articles I cited concluded that the research into the formation of homochirality during abiogenesis was unsuccessful.

Your habit of citing things out of context to justify your agenda is notorious and unethical.

The reference above states very explicitly that perfect homochirality is required. One section is even titled "No homochirality, no life".

Citation out of context of only one of the references in the article. IT ONLY REFERS TO COMPLEX RNA/DNA LIFE, and not the processes of abiogenesis that result in the evolution of RNA/DNA life.

[You can't tell me the best way? I only ask you to tell me the best way for homochirality to form, and let's discuss this.

I am not sure what you want to discuss. The articles only referred to 'successful' research that proposed different ways homochirality can take place in the natural processes of abiogenesis. As to which one is the best I will leave that up to future research, and neither of us are qualified to make that determination.

Alright then, so they need to address the chirality problem. But how is it that organic chemicals arrived in huge amounts? I need a reference...

Blessings,
Lee

You already have two references with numerous reference to the research that described the research concerning the evolution of homochirality during abiogenesis. These research articles reference and address the chirality problem.

[lee_merrill]

The Lurch repeatedly described that pure homochirality is not required in pre-life forms of abiogenesis, and the chemical processes of abiogenesis are what lead to the complex RNA/DNA life where homochirality evolved and the early pre-life forms do not require perfect homochirality.

Well, what about the RNA-world hypothesis, where the first biologically active molecule was a ribozyme?

No where in the articles I cited concluded that the research into the formation of homochirality during abiogenesis was unsuccessful.

Every one of the attempts was either a small chiral difference, or not applicable to early earth.

The reference above states very explicitly that perfect homochirality is required. One section is even titled "No homochirality, no life".

Citation out of context of only one of the references in the article. IT ONLY REFERS TO COMPLEX RNA/DNA LIFE, and not the processes of abiogenesis that result in the evolution of RNA/DNA life.

The quote is not "no homochirality, no complex rna/dna life", though.

I am not sure what you want to discuss. The articles only referred to 'successful' research that proposed different ways homochirality can take place in the natural processes of abiogenesis. As to which one is the best I will leave that up to future research, and neither of us are qualified to make that determination.

So let's have you pick a good method, then, and discuss that.

You already have two references with numerous reference to the research that described the research concerning the evolution of homochirality during abiogenesis. These research articles reference and address the chirality problem.

But I was asking for references about your claim that organic chemicals arrived in huge amounts.

Blessings,
Lee

[shunyadragon]

Well, what about the RNA-world hypothesis, where the first biologically active molecule was a ribozyme?

What about?!?!? I am not even addressing this in this topic.

Every one of the attempts was either a small chiral difference, or not applicable to early earth.

False.

The quote is not "no homochirality, no complex rna/dna life", though.

This is true, but you missed th epoint is "if homochirality does not evolve in abiogenesis there is no life.

Still selectively citing one liners to justify your agenda.

So let's have you pick a good method, then, and discuss that.

There are all good in one way or another, and there may be a combination. Pick this reference: https://cshperspectives.cshlp.org/co....full.pdf+html and go for it pick one, but it will be senseless. The problem is you have no qualifications in organic chemistry and abiogenesis to critique any one.


But I was asking for references about your claim that organic chemicals arrived in huge amounts.

Blessings,
Lee[/QUOTE]

[shunyadragon]

But I was asking for references about your claim that organic chemicals arrived in huge amounts.

Following is a beginning, more to follow . . .

Source: https://www.nature.com/articles/s41598-020-66112-8

08 June 2020
Impact-induced amino acid formation on Hadean Earth and Noachian Mars

© Copyright Original Source

[lee_merrill]

Following is a beginning, more to follow . . .

Source: https://www.nature.com/articles/s41598-020-66112-8

08 June 2020
Impact-induced amino acid formation on Hadean Earth and Noachian Mars
Yuto Takeuchi, Yoshihiro Furukawa, Takamichi Kobayashi, Toshimori Sekine, Naoki Terada & Takeshi Kakegawa
Scientific Reports volume 10, Article number: 9220 (2020) Cite this article

Although such local events might have provided reduced volatiles, the quantity of reduced species provided to the atmosphere remained unclear.

© Copyright Original Source

So this would not support huge amounts of organic chemicals arriving on early earth...

Blessings,
Lee

[shunyadragon]

So this would not support huge amounts of organic chemicals arriving on early earth...

Blessings,
Lee

The references document organics arriving and forming in large amounts during the asteroid impacts. Again your selective unethical dishonest citation of reverences to justify your agenda.

[lee_merrill]

The Lurch repeatedly described that pure homochirality is not required in pre-life forms of abiogenesis, and the chemical processes of abiogenesis are what lead to the complex RNA/DNA life where homochirality evolved and the early pre-life forms do not require perfect homochirality.

Well, what about the RNA-world hypothesis, where the first biologically active molecule was a ribozyme?

What about?!?!? I am not even addressing this in this topic.

But pure homochirality is required if the first active biomolecule was a ribozyme.

Every one of the attempts was either a small chiral difference, or not applicable to early earth.

False.

So which attempt was a large chiral difference applicable to early earth?

There are all good in one way or another, and there may be a combination. Pick this reference: https://cshperspectives.cshlp.org/co....full.pdf+html and go for it pick one, but it will be senseless. The problem is you have no qualifications in organic chemistry and abiogenesis to critique any one.

But this is another survey, I'm asking you to pick the best approach you have seen.

Blessings,
Lee