Donall and Conall Meet Richard Dawkins

Incredible when you think of Christ's praise of the lilies of the field, when just one E-coli cell is a miracle of creation, consummately sophisticated and breathtakingly beautiful. Even if its effects on our health leave a lot to be desired !Axel

April 29, 2015

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OT: Developments from the Study of Cells and Molecular Machines - April 28, 2015 Myosin Yet the stiff-legged motion seemed awkward at first -- something like a Monty Python "silly walk" sketch. But by filming the machines at 1000 frames per second, the Oxford scientists could see that the molecular machines' motion is anything but random or silly (see the animation above). "The movement resembles the twirling of a dividing compass used to measure distances on a map," chemist Philipp Kukura says. It's a bigger feat than first appears. "Think of it being rather like trying to walk a tightrope in a hurricane whilst being pelted with tennis balls.",,, RNA Polymerase This machine is responsible for transcribing DNA. Again, it's a lot more sophisticated than it first appeared. Research at Harvard shows that a fairy tale about it was in the scientists' imagination, not the cell: Once upon a time, scientists thought RNA polymerase -- the molecule that kicks off protein synthesis by transcribing DNA into RNA -- worked like a wind-up toy: Set it down at a start site in our DNA and it would whir steadily along, reeling off an RNA copy, until it reached the stop site. Lately, they've realized they didn't give RNA polymerase enough credit. "It's more like a high-performance sports car," said Stirling Churchman, assistant professor of genetics at Harvard Medical School. "It has to speed up, slow down and deal with obstacles in its path." In a one-minute video clip, Churchman explains why she is excited about the research, bringing at least a little clarity to a situation that often leaves her "overwhelmed by how complex it is," yet still manages to do its job. Her team found "a lot going on" as the machine proceeds down the DNA strand. The "sports cars" even know how to slow down for "speed bumps" and avoid head-on collisions. "Ultimately, it emphasizes the simplicity of our current views of how transcription occurs," Churchman says. http://www.evolutionnews.org/2015/04/developments_fr095581.htmlbornagain77

April 28, 2015

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