Life's biochemical networks could have formed spontaneously on Earth

Life’s biochemical networks could have formed spontaneously on Earth
Synthesis and breakdown of universal metabolic precursors promoted by iron Credit: University of Strasbourg

Researchers in Strasbourg, France, have found that mixing two small biomolecules, glyoxylate and pyruvate, in iron-salt-rich water produces a reaction network resembling life's core biochemistry. This discovery provides insight into how chemistry on the early Earth primed the evolution of the most ancient life. The study was published in the journal Nature

Scientists investigating the origins of on Earth have long struggled to explain how life's biochemistry got its start over 4 billion years ago. Biochemistry is organised around just five universal metabolic precursors built from C, O and H - just like heavy traffic in a big metropolis is organized around a few transit hubs. Why life uses the molecules and that it does, among countless alternatives, is a complete mystery.

A group of researchers led by Prof Joseph Moran at the University of Strasbourg has spent the past few years working on the origins of . "The idea that biological metabolism had a closely related chemical precursor that used similar intermediates and transformations is an attractive option," says Moran. Recently, the group recreated a purely chemical equivalent of the AcCoA pathway, a set of reactions used by microbes to produce acetate (two carbons) and pyruvate (three carbons) from CO2. Building compounds larger than three carbons from building blocks made from COwas where progress stalled. To accomplish such feats, life relies on complex enzymes and a chemical energy carrier, ATP. But both enzymes and ATP are complex structures that couldn't have existed on a lifeless Earth. How then did life build its biochemistry before enzymes and ATP?

Moran explains: "The breakthrough came from realizing that a chemical metabolism may have functioned in a slightly different way to the way it works in life today, while preserving the big picture." The team became inspired by the central role of a two-carbon metabolite, glyoxylate, in a model published earlier by theoretical biologist Daniel Segrè. Another clue came from organic chemists Ram Krishnamurthy and Greg Springsteen, who reported that pyruvate (three carbons) and glyoxylate (two carbons) easily react to form C-C bonds in water. Kamila Muchowska, a postdoctoral researcher in Moran's team and first author of the current study says, "We mixed glyoxylate and in warm, iron-rich water and noticed it gives rise to a network with over 20 biological intermediates, including ones that are as big as six carbons." Not only does the network increase in complexity over time, but it also breaks the intermediates back down to CO2, just like life does. "The life-like chemical system obtained this way conceptually resembles the function of biological anabolism and catabolism – no enzymes needed, just add iron," says Moran.

As part of the study, the researchers tested what happens if a source of nitrogen and a source of electrons are introduced into the system. "When we added hydroxylamine and metallic iron to the experiment, the reaction network produced four biological amino acids," explains Sreejith Varma, a co-author of the study. Moran says, "Interestingly, in the , those same four amino acids all have codons that starts with G, supporting ideas that metabolism and the genetic code may have emerged in parallel."

The newly discovered reaction network has so much in common with known biological cycles that the team wonders whether the Krebs and glyoxylate cycles could have had purely chemical origins. "We think metabolism could have built precursors of biological cycles this way, before ATP and enzymes existed," says Muchowska. The Strasbourg researchers are now eager to see how the reaction network can change in response to different elements, and whether it can lead to the molecules of genetics.


Explore further

Carbon dioxide and iron at the origin of life

More information: Kamila B. Muchowska et al. Synthesis and breakdown of universal metabolic precursors promoted by iron, Nature (2019). DOI: 10.1038/s41586-019-1151-1
Journal information: Nature

Citation: Life's biochemical networks could have formed spontaneously on Earth (2019, May 3) retrieved 20 August 2019 from https://phys.org/news/2019-05-life-biochemical-networks-spontaneously-earth.html
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May 03, 2019
I can't wait to read how the indigenous creationists will respond to this article. I imagine it will vary from "The researchers are blasphemous!" and "Only God can create life!" to "The researchers are deluding themselves via confirmation bias" and "Their water or beakers were surely contaminated". This is going to be fun..

May 03, 2019
Pun:
They seemed to have ironed out the 'origin' problem.
;-)
/

May 03, 2019
You throw the dice often enough?
An improbable combination of numbers will eventually occur.
& possibly, never again!

May 03, 2019
@Nik_223, It certainly adds weight to the argument, does it not? All Ionic Paths lead to Iron.

May 03, 2019
Stuart Kauffman back in the 1970 and 80s showed how a sufficiently diverse of molecules can self-assemble into a complex whole. Life didn't evolve from simple to complex; but, started out as a complex whole. This work proves this.

May 03, 2019
Prof Joseph Moran and his fellow researchers are the first humans to actually create a living thing. To make life from non-life.

May 03, 2019
This is a good extension to previous known Hadean bioservices. Like Keller glycolyis/pentose phosphate pathways [ https://www.ncbi....4023395/ ], which would act like glycogenesis - making glucose from 3C pyruvate . under product separation in sediments pores of a hydrothermal vent. Vent minerals would produce 2C and eventually 3C pyruvate from 1C (one carbon) ocean CO2 (and vent H2) without the article proposed need for CoA. The glyoxylate cycle [ https://en.wikipe...te_cycle ] is an evolutionary ancestor to the more complex and efficient citric acid cycle of central metabolism (itself proposed to be abiogenetic) [ https://en.wikipe...id_cycle ].

May 03, 2019
To wit, we now know that life evolved from hydrothermal vents providing bioservices (inorganics, biochemicals, replication) with no enzymes but mineral catalysts and natural RNA hot/cold cycling replication capability for the pathway between non life - half alive - life [ https://www.natur...l2016116 ; the half alive last common universal ancestor].

Stuart Kauffman ... showed ... self-assemble ... proves this.

Prof Joseph Moran and his fellow researchers ... create a living thing.


Neither of those two things are supported by the published work.

- Kauffman worked with self-catalytic cycles, here Fe2+ is the simple environmental catalyst.

- Moran showed an abiotic carbohydrate generating metabolism like chemical pathway, a step of what could have happened in the evolution from non-life to life.

Sure, it is a great step forward in filling out the details of the phylogenetic pathway between vents and independent cells on the chemical level.

May 03, 2019
A plausible mechanism. As long as it is not interpreted in a "primordial soup" or "pond" model.
These, as well as volcanic and sea-shore models suffer from extreme improbabilities resulting from physical issues such as flow and concentration. Most of which were very clearly identified in Robert Shapiro's 1975 book"Origins, a Skeptic's Guide to the Creation of Life on Earth". This I would strongly recommend as a "must read " because it very clearly details many of the issues to be resolved and the merits and demerits of various hypotheses.
Today, we have knowledge of the undersea alkaline thermal vents, a scenario which, as well as providing a solution to these prohibitive issues, also gives a mechanism whereby the matrices in the "foam" produced by the alkaline vents (but not the "black smokers) provide for evolution of the proto-cell membrane. The early chemistries described in the article may well have flourished and co-evolved in such an environment.

May 03, 2019
At first, even I had noted that this involves only two molecules; hardly the same thing as a diversity of molecules; but, then again ""We mixed glyoxylate and pyruvate in warm, iron-rich water and noticed it gives rise to a reaction network with over 20 biological intermediates,"

A reaction network of over twenty intermediates.

Whether this is lifelike to someone comes down to where they're going to draw the line.

May 03, 2019
Thanks for the proof that this must have occurred in deep sea vents(maybe not the black smokers). I've also had to deal with the ponds origins of life guys.

May 04, 2019
This is still very little different from the "achievement" of managing to arrange several molecules associated with life to form in atmosphere like what the "early earth" is claimed to have been like. The chemicals can be produced, but it is a long way to organizing, imbuing them with directed processes. They can produce long strings of interactions here, but each occurs only once. Basically, impressing individuals who are determined to be "impressed", convincing individuals who are determined to be "convinced".

May 04, 2019
oh juli. you & greddy * nenni & sillyegghead are expressing your jealousy that Scientists are miracle-workers.

& the best you trolling pestulants have to show for your magic-trick fakery?

Is total fail!

May 04, 2019
We're close to being able to re-run the Miller/Urey experiment with more realistic conditions, i.e. more complex, since Miller/Urey used only the simplest ices. For those not aware, those ices are methane, ammonia, and water. How can we simulate a smoker, and some of the cooler vents? Doesn't seem that hard.

May 05, 2019
Thinking of Ferroplasmaceae like Ferroplasma acidiphilum just on the opposite side of the canyon makes me like "Mmm, iron".
Hurry guys !

May 05, 2019
Today, we have knowledge of the undersea alkaline thermal vents, a scenario which, as well as providing a solution to these prohibitive issues, also gives a mechanism whereby the matrices in the "foam" produced by the alkaline vents (but not the "black smokers) provide for evolution of the proto-cell membrane. The early chemistries described in the article may well have flourished and co-evolved in such an environment.


Indeed, it is the alkaline vents that produce the complex organics, had the same redox potentials as modern cells, more often work at DNA/RNA melting temperatures suitable for inorganic replication, and life evolved from. Most such are located at ocean ridges where plates are produced from mantle flows in the progression inner acidic vents out to alkaline vents at the hydration zone of the mantle minerals,

But when we are interested in early evolution it is the alkaline vents that are most interesting.

May 05, 2019
How can we simulate a smoker, and some of the cooler vents? Doesn't seem that hard.


"In this paper, we discuss how prebiotic geo-electrochemical systems can be modeled as a fuel cell and how laboratory simulations of the origin of life in general can benefit from this systems-led approach. As a specific example, the components of what we have termed the "prebiotic fuel cell" (PFC) that operates at a putative Hadean hydrothermal vent are detailed, ..."

[ http://online.lie...014.1140 ]

Here is an update, of an acidic vent experiment that can produce Miller amino acids: https://www.forbe...afe747db . Early Earth was likely permeated with amino acids anyway, but any local ocean sources would dominate - and complement the biochemical sets for ice moons.

May 06, 2019
we now know that life evolved from hydrothermal vents
torbjorn_b_g_larsson

If what you really mean by "evolve from" is where the first life formed (abiogenesis), No, we don't "know" that. That is only one posiblity out of several and science has yet to show us which posiblity happened. We only know for sure that one of those several possibilities of abiogenesis happened (else, obviously, we wouldn't be here). Many (but not all) scientists researching this think abiogenesis probably didn't occur in a hydrothermal vent but rather probably occurred in a tidal pool on land; a perfectly reasonable hypothesis.

May 06, 2019
Why life uses the molecules and chemical reactions that it does, among countless alternatives, is a complete mystery.

It's actually quite simple - it was designed that way. Of course those hell-bent on a naturalistic explanation for life cannot countenance such a statement.
So to all the atheistic naturalists ( and theistic evolutionists too) I would suggest you read a little bit about the unzipping and zipping of the DNA molecule to see what you're up against for a purely naturalistic origin of life.
This here is on a creationist website but it is a simple statement of known and confirmed facts so far discovered regarding said process: https://creation....somerase . There is no need to throw a tantrum just because it's a creationist website. What is on this particular page is a summation of things you could have googled yourself. So please do have a look and see the hill to be climbed for a naturalistic origin of life.

May 06, 2019
Sahstar asked the question and FredyJ delivered.

May 06, 2019
The breakthrough came from realizing that a chemical metabolism may have functioned in a slightly different way to the way it works in life today

This is simply another way of grasping at straw in order to avoid drowning. It was not that it was discovered and can be verified that such chemical metabolism actually exists but rather a hail-Mary last ditch sheer speculation that such a rescue device will be discovered.
So this whole research is based on another phantom.

People just don't want to accept that it is impossible to overcome all the requirements for a naturalistic origin of life - because the alternative is just horrifically terrifying - accountability to a Holy Creator. Therein lies the rub - they recognize their insufficiency w.r.g.t holiness but they are unwilling to accept the righteousness that is freely available to everyone.
This is called foolishness. Or sheer utter madness given the ultimate fiery outcome that is drawing closer each second.

May 06, 2019
Sahstar asked the question and FredyJ delivered.

But did you even bother to read the web page? If you did, what is your opinion of it? If you didn't, why not? Are you afraid of science? Are you a science denier?

May 06, 2019
abiogenesis probably didn't occur in a hydrothermal vent but rather probably occurred in a tidal pool on land; a perfectly reasonable hypothesis.

On closer examination, though, it turns out that it might not be such a sanguine environment after all - chemical reactions tend to move to an equilibrium condition rather quickly. This means that no matter what ingredients for life might appear they will just as quickly disappear in such a watery environment. In fact water is not what you want in the mix with bare and exposed ingredients because it's hostile to most of the exposed ingredients of life - ironic really, given that water is so desperately needed for life!
All people who deny THE Creator will just have to go thru the rest of their lives ever-searching, ever-hoping for that fabulous naturalistic origin of life to be found. Alas, they will die in their sin with the consequences that that brings along with it.

May 06, 2019
Why life uses the molecules and chemical reactions that it does, among countless alternatives, is a complete mystery.

It's actually quite simple - it was designed that way.
FredJose

Simple if there is a god or gods. But the assumption that there is a god or gods is completely baseless.
A far better and more rational explanation is that the very first life starting with whatever basic building blocks it did by chance so it could have but didn't start with alternative ones but then evolution quickly made it increasingly rely on those same building blocks thus quickly making it harder and harder for life to evolve to change them. In other words, once life starts with whatever basic building blocks it does, evolution cannot credibly change those building blocks thus life is stuck with them even if those particular basic building blocks aren't the optimum ones. This completely explains why all known life today is built on the same building blocks.

May 06, 2019
Sahstar asked the question and FredyJ delivered.

But did you even bother to read the web page? If you did, what is your opinion of it? If you didn't, why not? Are you afraid of science? Are you a science denier?


No, I'm not a science denier, that is why I won't waste time on creationist drivel.

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