Word: helix
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Watson had sketched out how four chemical bases paired to create a self-copying code at the core of the double-helix-shaped DNA molecule. In the more formal announcement of their discovery, a one-page paper in the journal Nature, they noted the significance in a famously understated sentence: "It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic material." But they were less restrained when persuading Watson's sister to type up the paper for them. "We told her," Watson wrote in The Double Helix, "that...
...work." And her role didn't end there. Her critique of an early Watson and Crick theory had sent them back to the drawing board, and her notebooks show her working toward the solution until they found it; she had narrowed the structure down to some sort of double helix. But she never employed a key tool--the big 3-D molecular models that Watson and Crick were fiddling with at Cambridge...
Here--in the "complementarity" between A and T, between C and G--lay the key to replication. In the double helix, a single strand of genetic alphabet--say, CAT--is paired, rung by rung, with its complementary strand, GTA. When the helix unzips, the complementary strand becomes a template; its G, T and A bases naturally attract bases that amount to a carbon copy of the original strand, CAT. A new double helix has been built...
...double helix--both the book and the molecule--did nothing to slow this century's erosion of innocence. Watson's account, depicting researchers as competitive and spiteful--as human--helped de-deify scientists and bring cynicism to science writing. And DNA, once unveiled, left little room for the ethereal, vitalistic accounts of life that so many people had found comforting. Indeed, Crick, a confirmed agnostic, rather liked deflating vitalism--a mission he pursued with zeal, spearheading decades of work on how exactly DNA builds things before he moved on to do brain research at the Salk Institute for Biological Studies...
...practical and philosophical issues opened by the double helix continue to unfold, policy, philosophy and even religion will evolve in response. But one truth seems likely to endure, universal and immutable. It emerges with equal clarity whether you examine the DNA molecule or the way it was revealed. The secret of life is complementarity...