Featured Research

from universities, journals, and other organizations

How Did Chemical Constituents Essential To Life Arise On Primitive Earth?

Date:
October 31, 2007
Source:
University of Georgia
Summary:
Chemists now proposed the first detailed, feasible mechanism to explain how adenine, one of the four building blocks of DNA, might be built up from the combination of five cyanide molecules. The investigation is based on extensive quantum chemical computations over several years.

DNA is the nucleic acid blueprint of life that is passed on from generation to generation.
Credit: iStockphoto/Sunagatov Dmitry

Experiments show that simple molecules can combine chemically rather than biologically to form the building blocks of DNA, the key component of all life forms. These processes might have taken place on primitive earth, but how they occur is an unsolved puzzle.

Chemists at the University of Georgia have now proposed the first detailed, feasible mechanism to explain how adenine, one of the four building blocks of DNA, might be built up from the combination of five cyanide molecules. The investigation is based on extensive quantum chemical computations over several years.

"Just where these biomolecules originated isn't known," said Paul von Raguι Schleyer, Graham Perdue Professor of Chemistry at the University of Georgia. "One can only speculate. They could have formed from smaller molecules present on primitive Earth, either very slowly over millions of years or rapidly before the Earth cooled down. Asteroids may have brought them from outer space, but how did biomolecules form there?"

The newly proposed mechanism for the formation of adenine gives a clear picture of how it could have become one of the building blocks essential for the formation of DNA. The research was published in the Proceedings of the National Academies of Science. Schleyer's coworkers were Ph. D. candidate Debjani Roy, the first author of the paper, and Katayoun Najafian, his former student from Iran.

DNA is the nucleic acid blueprint of life that is passed on from generation to generation. First isolated in 1869 from the pus of discarded surgical bandages by Friedrich Miescher, a Swiss doctor, DNA's double helix structure was solved by Watson and Crick in 1953. DNA is shaped somewhat like a twisted ladder with the rungs anchored by matching pairs of only four bases: adenine, guanine, cytosine and thymine.

The UGA chemists focused on adenine because of its relative prevalence on Earth and its formation in the dark in from simple components. Along with other fundamental building blocks, adenine has even been detected extraterrestrially. Still, the vast distance between the smaller molecules required to form adenine in outer space precludes its formation, unless some nucleation centers, like specks of interstellar dust, are present.

"Numerous experiments have demonstrated that amino acids, nucleotides, carbohydrates and other essential compounds form under simulated primitive Earth conditions," the authors write in their paper.

Remarkably, a solution of highly poisonous cyanide in ammonia, frozen solid in a refrigerator for 25 years, produced adenine, a necessary component of life. A substantial amount of adenine also was formed in a high-temperature experiment designed to simulate early volcano-like environments. But the question is how.

The Georgia researchers arrived at an answer by solving a series of key riddles. They worked out the processes in which five cyanide molecules might combine to form adenine under terrestrial conditions. Their predictions are based on extensive computations of sequences of reaction steps along possible mechanistic routes.

"Finding a viable, thermodynamically feasible, step-by-step mechanism that can account for the formation of adenine was far from straightforward," the authors said. "Our report provides a more detailed understanding of some of the chemical process involved in chemical evolution, and a partial answer to the fundamental question of molecular biogenesis. Our investigation should trigger similar investigations of the abiotic formation of the remaining nucleic acid bases as well as other biologically relevant molecules."


Story Source:

The above story is based on materials provided by University of Georgia. Note: Materials may be edited for content and length.


Cite This Page:

University of Georgia. "How Did Chemical Constituents Essential To Life Arise On Primitive Earth?." ScienceDaily. ScienceDaily, 31 October 2007. <www.sciencedaily.com/releases/2007/10/071030114051.htm>.
University of Georgia. (2007, October 31). How Did Chemical Constituents Essential To Life Arise On Primitive Earth?. ScienceDaily. Retrieved October 2, 2014 from www.sciencedaily.com/releases/2007/10/071030114051.htm
University of Georgia. "How Did Chemical Constituents Essential To Life Arise On Primitive Earth?." ScienceDaily. www.sciencedaily.com/releases/2007/10/071030114051.htm (accessed October 2, 2014).

Share This



More Fossils & Ruins News

Thursday, October 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Japan Celebrates 'bullet Train' Anniversary

Raw: Japan Celebrates 'bullet Train' Anniversary

AP (Oct. 1, 2014) — A ceremony marking 50 years since Japan launched its Shinkansen bullet train was held on Wednesday in Tokyo. The latest model can travel from Tokyo to Osaka, a distance of 319 miles, in two hours and 25 minutes. (Oct. 1) Video provided by AP
Powered by NewsLook.com
Battle of New Orleans Cannon Gets New Carriage

Battle of New Orleans Cannon Gets New Carriage

AP (Sep. 30, 2014) — A Spanish cannon used in the Battle of New Orleans and weighing nearly 3 tons was lowered Tuesday by pulleys, chains and muscle onto a new gun carriage like one that might have held it once aboard a navy ship. (Sept. 30) Video provided by AP
Powered by NewsLook.com
2,000 Year Old Pre-Inca Cloak on Display in Lima

2,000 Year Old Pre-Inca Cloak on Display in Lima

AFP (Sep. 27, 2014) — A 2,000 year-old Pre-Inca cloak that is believed to represent an agricultural calendar of the Paracas culture is on display in Lima. Duration: 00:39 Video provided by AFP
Powered by NewsLook.com
Original Mozart Sonata Manuscript Found in Budapest

Original Mozart Sonata Manuscript Found in Budapest

AFP (Sep. 26, 2014) — Considered lost for over two centuries, the original manuscript of one of the most famous works of Mozart's Sonata in A major has been uncovered in a library in Budapest. Duration: 01:04 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins