Word: cricks
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Dates: during 1970-1979
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Implicit in the Watson-Crick model were the workings of DNA's other essential function: how it orders the production of proteins. These are also long and twisted helical molecules, but they are the actual building blocks rather than the genetic blueprints for living things. As such, proteins are immensely varied; there are many thousands of different kinds in the human body alone. The distinctive proteins that make up the cells of the eye, for example, differ from those of the kidneys or muscles. Despite their variety, however, all proteins are built from some of only 20 smaller and simpler...
...after wrestling with the question, Francis Crick postulated (and Harvard Biochemists Paul Zamecnik and Mahlon Hoagland confirmed) a second form of RNA, which was later found to carry specific amino acids floating in the cytoplasm to the 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...
...CRICK'S team at Cambridge proved Gamow's ingenious "triplet" theory. They demonstrated that RNA formed from only one or two base units could not effect the manufacture of proteins. But when they added a third base unit, protein formation began immediately. It remained, however, for an unknown young biochemist named Marshall Nirenberg, at the National Institutes of Health, to crack the code itself. That same year Nirenberg had succeeded in building up short, synthetic strands of RNA out of only one type of base. Invariably, this artificial RNA induced the manufacture of chains of proteins consisting of only...
That process, shown in the 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...
...technical men who understand them. Even if government does enter the field, points out Daniel Callahan, much of the success of any ethical policy will depend on a responsible professional code. "If you depend solely on laws, sanctions and enforcements," says Callahan, "the game is over." Molecular Biologist Francis Crick is confident that basic morals and common sense will prevail. Some of the wilder genetic proposals will never be adopted, he claims, because "people will simply not stand for them...