Impact of temperature on the time required for the establishment of primordial biochemistry, and for the evolution of enzymes. 2010.R. B. Stockbridge, et al. PNAS,
published online before print December 1.Enzymes, proteins that jump-start chemical reactions, are essential to life within cells of the human body and throughout nature. To appreciate how powerful modern enzymes are, and the process of how they evolved, researchers measured the speed of chemical reactions. They estimated that
some reactions take more than 2 billion years without an enzyme. In the process of measuring slow reaction rates, "it gradually dawned on us that the slowest reactions are also the most temperature-dependent," Wolfenden said.
In general, the amount of influence temperature has on reaction speeds varies drastically, the group found. In one slow reaction, for instance,
raising the temperature from 25 to 100 degrees Celsius increases the reaction rate 10 million fold. High temperatures were probably a crucial influence on reaction rates when life began forming in hot springs and submarine vents. Later, the cooling of the earth provided selective pressure for primitive enzymes to evolve and become more sophisticated.
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