glycolysis pathway cannot evolved?? confused:(

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anarcho
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glycolysis pathway cannot evolved?? confused:(

Post by anarcho » Tue Nov 08, 2005 4:42 am

I have these argument from my teacher and I dont know how to answer, i tried to but i confused how to answer with the right words. This is the argument:

It may be argued that the glycolysis pathway cannot possibly have evolved for two reasons. First, there are too many intermediate steps that must be present to produce the final product (pyruvate), and second, it actually requires an input of energy to get started.


Thank you so much in advance if you can help me, i would really appreciate.

Thanks again

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mith
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Post by mith » Tue Nov 08, 2005 5:28 am

Manfred Eigen showed in the 1960's how, given a constant supply of energy, enzymes can form into catalytic networks that often include closed loops (read: feedback). Providing the flow of energy is sufficient to maintain a state far from equilibrium these catalytic cycles self-organize and with enough time and energy "catalytic cycles tend to interlock to form closed loops in which the enzymes produced in one cycle act as catalysts in the subsequent cycle." These interlocking catalytic chains which he calls hypercycles are remarkably stable and can even give rise to a form of self-replication.

Sounds like an irreducible complexity argument.

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anarcho
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Post by anarcho » Tue Nov 08, 2005 5:35 am

I dont know if it's tru or not

First primitive biochemical processes Energy-rich molecules scavenged from the environment Molecules existed in the existing organic soup
Catalyzed reactions were simple one-step processes as energy-rich molecules were depleted only those cells that could synthesize energy-rich molecules could survive Energy utilizing reaction became coupled to energy-producing reaction Evolution of pathways works backwards Occur one step at a time Final reactions generally evolve first, initial reaction evolves last

http://www.mhhe.com/biosci/genbio/rjbio ... /ELO8.html

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