Kinesin Is A Molecular Machine


Kinesin may be viewed at 1:15

Flailing Blindly: The Pseudoscience of Josh Rosenau and Carl Zimmer

Jonathan Wells:

“But that’s not what the biological evidence shows. In fact, kinesin moves quickly, with precise movements, to get from one place to another. A kinesin molecule takes one 8-nanometer “step” along a microtubule for every high-energy ATP molecule it uses, and it uses about 80 ATPs per second. On the scale of a living cell, this movement is very fast. To visualize it on a macroscopic scale, imagine a microtubule as a one-lane road and the kinesin molecule as an automobile. The kinesin would be traveling over 200 miles per hour! The fact that the cell’s cytoplasm is quite crowded makes this even more remarkable — like an automobile going 200 miles per hour through a traffic jam. So on what basis (other than the new animation) does Zimmer claim that kinesin molecules “flail blindly” with “barely constrained randomness”?

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