27 July 2007

DNA Replication, up close and personal

This animation illuminates how the molecular basis of life is understood through today's research, with profound implications for medicine. Blogger "Xantox" explains of this video from The Walter & Eliza Hall Institute in Australia,

Using computer animation based on molecular research it is possible to see how DNA is actually copied in living cells. This animation shows the “assembly line” of biochemical machines which pull apart the DNA double helix and output a copy of each strand. The DNA to be copied enters the whirling blue molecular machine, called helicase, which spins it as fast as a jet engine as it unwinds the double helix into two strands. One strand is copied continuously, and can be seen spooling off on the other side. Things are not so simple for the other strand, because it must be copied backwards, so it is drawn out repeatedly in loops and copied one section at a time. The end result is two new DNA molecules.
What you see here is occurring countless billions of times in your body right now. It gets even more wondrous: research by Steven Block and his students and post-docs at Stanford University show that processes like this essentially edit their own work. The discovery mechanism for all this is the astonishing nanotech tool of optical tweezers. See my article on that from Biophotonics International here.

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