Navigation Links
Reconstructed ancient ocean reveals secrets about the origin of life
Date:4/25/2014

HEIDELBERG, 25 April 2014 Researchers from the University of Cambridge have published details about how the first organisms on Earth could have become metabolically active. The results, which are reported in the journal Molecular Systems Biology, permit scientists to speculate how primitive cells learned to synthesize their organic components the molecules that form RNA, lipids and amino acids. The findings also suggest an order for the sequence of events that led to the origin of life.

A reconstruction of Earth's earliest ocean in the laboratory revealed the spontaneous occurrence of the chemical reactions used by modern cells to synthesize many of the crucial organic molecules of metabolism. Previously, it was assumed that these reactions were carried out in modern cells by metabolic enzymes, highly complex molecular machines that came into existence during the evolution of modern organisms.

Almost 4 billion years ago life on Earth began in iron-rich oceans that dominated the surface of the planet. An open question for scientists is when and how cellular metabolism, the network of chemical reactions necessary to produce nucleic acids, amino acids and lipids, the building blocks of life, appeared on the scene.

The observed chemical reactions occurred in the absence of enzymes but were made possible by the chemical molecules found in the Archean sea. Finding a series of reactions that resembles the "core of cellular metabolism" suggests that metabolism predates the origin of life. This implies that, at least initially, metabolism may not have been shaped by evolution but by molecules like RNA formed through the chemical conditions that prevailed in the earliest oceans.

"Our results demonstrate that the conditions and molecules found in the Earth's ancient oceans assisted and accelerated the interconversion of metabolites that in modern organisms make up glycolysis and the pentose-phosphate pathways, two of the essential and most centrally placed reaction cascades of metabolism," says Dr. Markus Ralser, Group Leader at the Department of Biochemistry at the University of Cambridge and the National Institute for Medical Research. "In our reconstructed version of the ancient Archean ocean, these metabolic reactions were particularly sensitive to the presence of ferrous iron that helped catalyze many of the chemical reactions that we observed." From the analysis of early oceanic sediments, geoscientists such as Alexandra V. Turchyn from the Department of Earth Sciences at the University of Cambridge, one of the co-authors of the study, concluded that soluble forms of iron were one of the most frequently found molecules in the prebiotic oceans.

The scientists reconstructed the conditions of this prebiotic sea based on the composition of various early sediments described in the scientific literature. The different metabolites were incubated at high temperatures (50-90oC) similar to what might be expected close to a hydrothermal vent of an oceanic volcano, a temperature that would not support the activity of conventional protein enzymes. The chemical products were separated and analyzed by liquid chromatography tandem mass spectrometry.

Some of the observed reactions could also take place in water but were accelerated by the presence of metals that served as catalysts. "In the presence of iron and other compounds found in the oceanic sediments, 29 metabolic-like chemical reactions were observed, including those that produce some of the essential chemicals of metabolism, for example precursors of the building blocks of proteins or RNA," says Ralser. "These results indicate that the basic architecture of the modern metabolic network could have originated from the chemical and physical constraints that existed on the prebiotic Earth."

The detection of one of the metabolites, ribose 5-phosphate, in the reaction mixtures is particularly noteworthy. Its availability means that RNA precursors could in theory give rise to RNA molecules that encode information, catalyze chemical reactions and replicate. Whether and how the first enzymes adopted the metal-catalyzed reactions described by the scientists remain to be established.


'/>"/>
Contact: Barry Whyte
barry.whyte@embo.org
European Molecular Biology Organization
Source:Eurekalert  

Related biology news :

1. Ancient DNA offers clues to how barnyard chickens came to be
2. Ancient sea-levels give new clues on ice ages
3. Scientists reconstruct ancient impact that dwarfs dinosaur-extinction blast
4. Study: Black carbon is ancient by the time it reaches seafloor
5. Ancient shrimp-like animals had modern hearts and blood vessels
6. GSA Bulletin: Rock avalanches, ancient weather, astronomical clocks, anoxia, and volcanism
7. Ancient African cattle first domesticated in Middle East, MU study reveals
8. Ancient clam gardens nurture food security
9. Ancient food webs developed modern structure soon after mass extinction
10. Ancient DNA shows moa were fine until humans arrived
11. Climate of Genghis Khans ancient time extends long shadow over Asia of today
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Reconstructed ancient ocean reveals secrets about the origin of life
(Date:8/15/2017)... Va. , Aug. 15 2017   ivWatch LLC , ... of intravenous (IV) therapy, today announced receipt of its ISO 13485 ... developed by the International Organization for Standardization (ISO®). ... ivWatch Model 400 Continuous Monitoring device for the ... "This is ...
(Date:5/23/2017)... , May 23, 2017  Hunova, the first robotic gym for the ... been officially launched in Genoa, Italy . The first ... and the USA . The technology was developed ... market by the IIT spin-off Movendo Technology thanks to a 10 million ... News Release, please click: ...
(Date:4/19/2017)... ALBANY, New York , April 19, 2017 /PRNewswire/ ... highly competitive, as its vendor landscape is marked by ... in the market is however held by five major ... and Safran. Together these companies accounted for nearly 61% ... majority of the leading companies in the global military ...
Breaking Biology News(10 mins):
(Date:10/10/2017)... (PRWEB) , ... October 10, 2017 , ... ... Science Center’s FirstHand program has won a US2020 STEM Mentoring Award. Representatives of ... award for Excellence in Volunteer Experience from US2020. , US2020’s mission is to ...
(Date:10/10/2017)... -- International research firm Parks Associates announced today that ... TMA 2017 Annual Meeting , October 11 in Scottsdale, Arizona ... market and how smart safety and security products impact the competitive landscape. ... Parks Associates: Smart Home Devices: Main Purchase ... "The residential security market has experienced continued growth, ...
(Date:10/10/2017)... BARBARA, CALIFORNIA (PRWEB) , ... October 10, 2017 ... ... management, technological innovation and business process optimization firm for the life sciences and ... BoxWorks conference in San Francisco. , The presentation, “Automating GxP Validation ...
(Date:10/9/2017)... SAN DIEGO , Oct. 9, 2017 /PRNewswire/ ... a biological mechanism by which its ProCell stem ... of critical limb ischemia.  The Company, demonstrated that ... the amount of limbs saved as compared to ... of the molecule HGF resulted in reduction of ...
Breaking Biology Technology: