Word: molecular
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Dates: during 1970-1979
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...shape of a helix, or spiral. From the X-ray crystallography laboratory at King's College in London, where Biochemist Maurice Wilkins was also investigating the molecule's structure, they quietly obtained unpublished X-ray data on DNA. Relying as much on luck as logic, they constructed Tinkertoy-like molecular models out of wire and other metal parts. To everyone's astonishment, they suddenly produced a DNA model that not only satisfied the crystallographic evidence but also conformed to the chemical rules for fitting its many atoms together...
...ribosomes; this substance became known as transfer RNA. Then in the early 1960s, biologists discovered a third kind of RNA?shortly after its existence had been theorized by Jacques Monod and François Jacob of France's Pasteur Institute. Called messenger RNA, it provided the missing piece in the molecular puzzle. It was formed on an uncoiled strip of DNA in the nucleus, imprinted with the particular "message" encoded in that portion?or gene?of the staircase, and then sent off with these instructions to the protein-making ribosomes...
...accompanying color chart, was summarized by Crick in a series of rules that became known as the Central Dogma. Most scientists interpreted the key rule of that dogma to be that genetic information flowed in one direction: from DNA to RNA to protein. To the surprise of many molecular biologists, however, it has recently been shown that part of the process can sometimes be reversed. This finding, in the opinion of molecular biologists like Columbia's Sol Spiegelman, may offer an important clue to the workings of cancer cells (see box, page...
...Molecular biologists are also probing ever more deeply into the process of cell differentiation. It has long been known that the DNA in every body cell of an individual organism is identical; this DNA contains all the information necessary to construct the whole organism. Why then, in a human being, for example, is a liver cell so different from a hair cell, a heart cell so different from a skin cell? The answer, Jacob and Monod theorized in 1961, is that only a small percentage of the genes in any cell are giving instructions for the operation of that particular...
...remarkable advances in molecular biology during the past two decades have given man an understanding of the basic processes that shape his life and have placed within the realm of possibility medical achievements undreamed of a scant few years ago. As more and more of the once-mysterious life forces within the cell are defined in the logical language of chemistry, the way is being opened not only for permanent cures of genetic diseases but also for drastic changes in man's genetic makeup. The acquisition of the power to eliminate genetic imperfections and engineer entirely new characteristics for humans...