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Ross/NAS
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Ocean waves continue to wash through our every cell, say Masa Tsuchiya and John Ross (Stanford University, Stanford, CA). They have found that oscillatory metabolism〞a more efficient method of creating chemical energy even with constant nutrient inputs〞develops faster and more efficiently in response to oscillatory inputs such as the wash of nutrients from seashore waves. Thus such metabolism may have arisen at the seashore and then spread over the rest of the Earth.
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/ b7 e/ ~4 E: ^3 ?: Z2 w: \8 mOscillatory metabolism has been seen in reactions such as glycolysis and proton import into mitochondria. The Stanford group earlier showed that oscillatory metabolism can be more efficient than linear metabolism as the oscillations force large amounts of reactants through a reaction when the reactant to product ratio is at its maximum. (This is comparable to the rush of electrical current at the peak voltage of an alternating current network.)% o" t+ l- [( g4 {9 m
9 G" ?! Q2 ^5 j: aBut how did the oscillations first arise? After staring at waves in a cove in La Jolla, CA, and seeing a paper stating that wave- exposed organisms can grow faster, Ross had his idea: the waves did it. He modeled glycolysis as an evolving genetic algorithm. As the algorithm ran, systems with a constant influx of glucose took about double the number of generations to reach the more efficient oscillatory state than did systems with an oscillatory influx. Furthermore, the algorithms with an oscillatory input reached a higher final efficiency, as measured by the ATP:ADP ratio.9 n% Y/ {7 A4 n+ ]7 ]$ E. y9 {& P
" I6 n2 y1 u- w0 R2 [# BMost biologists continue to focus on linear metabolism. Ross believes that eventually this will change, and that waves will get due recognition for forming not just cliffs but metabolism.$ G- e& o, @5 U$ U; u, C" C
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5 w0 e4 t! a; {! jTsuchiya, M., and J. Ross. 2003. Proc. Natl. Acad. Sci. USA. 100:9691–9695.(An oscillatory influx of nutrients (bott) |
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发表于 2009-3-6 00:48
发表于 2015-5-22 15:34
