What lowers activation energy in enzymes?

What lowers activation energy in enzymes?
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This is the most important concern of Biochemistry, theenzyme-catalyzed reactions. The main factor that lowers theactivation energy, is the catalysis. Catalysts act by reducing theactivation barrier for the reaction being catalyzed. Thus, a10-fold rate requires less than the free energy of a typicalhydrogen bond; a million-fold rate acceleration occurs only with asmall fraction of the energy of most covalent bonds.
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