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When life began on Earth, iron may have done the job of magnesium,making life possible. On the periodic table of the elements, ironand magnesium are far apart. But new evidence discovered by theNASA Astrobiology Institute (NAI) team at the Georgia Institute ofTechnology suggests that three billion years ago, iron did the jobmagnesium does today in helping Ribonucleic acid (RNA), a moleculeessential for life, assume the molecular shapes necessary forbiology. The results of the study are scheduled to be published online inthe journal PLoS ONE. There is considerable evidence that the evolution of life passedthrough an early stage when RNA played a more central role, doingthe jobs of DNA and protein before they appeared. During that time,more than three billion years ago, the environment lacked oxygenbut had lots of available iron. "One of the greatest challenges in astrobiology is understandinghow life began on Earth billions of years ago when the environmentwas very different than it is today," said Carl Pilcher, directorof the Astrobiology Institute at NASA's Ames Research CenterMoffett Field, Calif. "This study shows us how conditions on early Earth may have beenconducive to the development of life." In the new study, researchers from the Georgia Institute ofTechnology, Atlanta, used experiments and numerical calculations toshow that under early Earth conditions, with little oxygen around,iron can substitute for magnesium in RNA, enabling it to assume theshapes it needs to catalyze life's chemical reactions. In fact, itcatalyzed those reactions better with iron than with magnesium. "The primary motivation of this work was to understand RNA underplausible early Earth conditions." said Loren Williams, a professorin the School of Chemistry and Biochemistry at Georgia Tech andleader of the NAI team. "Our hypothesis is that RNA evolved in thepresence of iron and is optimized to work with iron." Free oxygen gas was almost nonexistent more than three billionyears ago in early Earth's atmosphere. When oxygen began enteringthe environment as a product of photosynthesis, it turned Earth'savailable iron to rust, forming massive banded iron deposits thatare still mined today. When all that iron got tied up in those deposits, it was no longeravailable. The current study indicates that RNA then began usingmagnesium, resulting in life as we know it today. In future studies, the researchers plan to investigate what uniquefunctions RNA can perform with iron that are not possible withmagnesium. In addition to Williams, Georgia Tech School of Biologypostdoctoral fellow Shreyas Athavale, research scientist AntonPetrov, and professors Roger Wartell and Stephen Harvey, andGeorgia Tech School of Chemistry and Biochemistry postdoctoralfellow Chiaolong Hsiao and professor Nicholas Hud also contributedto this research. This study was funded by the NASA Astrobiology Institute, a virtualinstitute located and managed at NASA Ames Research Center, MoffettField, Calif. I am an expert from healthy-e-cigarette.com, while we provides the quality product, such as E-cig Cartomizers , Joye Ego-T, Electronic Health Cigarette,and more.
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