Word: rna
(lookup in dictionary)
(lookup stats)
Dates: during 1980-1989
Sort By: most recent first
(reverse)
Biology students used to be taught that there was a strict division of labor within living cells. The nucleic acids, DNA and RNA, served as repositories of genetic information, and certain proteins, called enzymes, did all the work. But research conducted in the past decade by Sidney Altman of Yale University and Thomas Cech of the University of Colorado at Boulder has forced scientists to alter completely their ideas not only of how cells function but also of how life on earth began. Last week the Nobel Prize for Chemistry went to Altman and Cech, with the citation that "many...
Working with a bacterium and a pond-dwelling protozoan, Altman, 50, and Cech, 41, independently discovered that RNA can act as an enzyme, a molecule that accelerates chemical reactions a millionfold or more and makes it possible for life to exist. Plants, for example, depend on enzymes to convert carbon dioxide in the air to sugar and starch. An enzyme in human saliva helps transform starch into glucose, the body's energy source. Until RNA enzymes were identified, all enzymes were thought to be proteins...
Cech also found that RNA can copy itself, suggesting that the first living organisms may not have depended solely on DNA, the principal carrier of hereditary information in plants, animals and bacteria. "Now that we know that RNA can both carry genetic information and serve as a catalyst," Cech wrote last year, "it seems possible that it was the key molecule at the origin of life...
FOOTNOTE: *A virus consisting largely of RNA, a single-stranded chain of bases similar to the DNA double helix...
...virus, whether biological or electronic, is basically an information disorder. Biological viruses are tiny scraps of genetic code -- DNA or RNA -- that can take over the machinery of a living cell and trick it into making thousands of flawless replicas of the original virus. Like its biological counterpart, a computer virus carries in its instructional code the recipe for making perfect copies of itself. Lodged in a host computer, the typical virus takes temporary control of the computer's disk operating system. Then, whenever the infected computer comes in contact with an uninfected piece of software, a fresh copy...