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26 de abril de 2024
dulces piedrazos
Descubren azúcares vitales en los meteoritos sábado 30 de noviembre de 2019 17:36 Las pruebas se tomaron sobre el meteorito Murchison.
Washington . Los científicos han detectado en meteoritos la presencia de ribosa y otros azúcares, que son elementos esenciales de los sistemas biológicos, lo que puede indicar el origen extraterrestre de estas sustancias, según un estudio publicado en la revista Proceedings of the National Academy of Sciences . "Los azúcares son moléculas esenciales para todos los organismos vivos terrestres y operan en muchos procesos biológicos", escribieron los científicos encabezados por Yoshihiro Furukawa, del Departamento de Ciencias de la Tierra en la Universidad Tohoku, de Sendai (Japón). La ribosa es particularmente esencial como bloque en la construcción del ácido ribonucleico, uno de los dos ácidos en el núcleo de las células junto con el desoxirribonucleico. Este azúcar "podría haber almacenado a la vez información y catalizado reacciones en la vida primitiva de la Tierra", añadieron los expertos. "Los meteoritos contienen numerosos compuestos orgánicos incluidos los bloques clave en la construcción de la vida como aminoácidos, nuclebases y fosfato". Furukawa y sus colegas analizaron tres meteoritos de condrita carbonatada, incluido el meteorito Murchison, que cayó en Victoria, Australia, en 1969 y es uno de los más estudiados debido a su masa de casi 100 kilogramos. El hallazgo de ribosa y otros azúcares biológicamente importantes indica que estos compuestos son de origen extraterrestre y no resultado de la contaminación terrestre. Los científicos llevaron a cabo en el laboratorio simulacros experimentales para aproximarse a las condiciones bajo las que tales azúcares pueden haberse formado en el espacio y concluyeron que la reacción de la formosa, que produce azúcares a partir de aldehídos, puede haber generado tales azúcares. La composición mineral de estos meteoritos indica, además, que la formación de estos azúcares ocurrió tanto antes como después de la acumulación de los asteroides de donde proceden. Los meteoritos transportaron moléculas orgánicas precursoras de la vida a la Tierra. De esta manera la detección de azúcares extraterrestres en los meteoritos establece la existencia de rutas geológicas naturales para su formación y preservación, como asimismo la posibilidad de que los azúcares extraterrestres hayan contribuido a la formación de biopolímeros funcionales en la Tierra temprana u otros mundos primitivos.
EFE