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Help on Enzyme Catalysts - (Oct/31/2013 )

Hey all, just had some difficulty understanding these statements.

Was wondering if I could get some help. Thanks.


True or False?


1) Enzymes exhibit high stereospecificity, even on prochiral substrates, for example,distinguishing between different hydrogens on the same carbon of NAD(P)H. 


2) Enzymes can enhance the spontaneity of a reaction, i.e. convert a process ( A-->B )that is endergonic so that it is exergonic.


3) By optimizing the proximity and orientation of substrates and key catalytic residues in the active site, an enzyme can couple two half reactions, one highly exergonic, the other somewhat endergonic, to yield an overall thermodynamically favorable reaction. 


4) Enzymes accelerate biological reactions by preferential binding to the ground state, as demonstrated by the development of catalytic antibodies. 


5) As catalysts, enzymes are not consumed during the reaction process, but are able to turn over multiple times. This precludes covalent modification of the enzyme as part of the

catalytic process.
Any help would be appreciated. Thanks again.


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