Question

2 ways enzymes effect chemical reactions

Answer 1

It acts as a catalyst to accelerate the rate and specificity of a reaction

Answer 2

http://en.wikipedia.org/wiki/Enzyme

Answer 3

An enzyme, can effect Biochemical reaction
1) Increases the rate of the reaction, by decreasing the activation energy (The energy required to initiate the conversion of reactants into products).

Activation energy barriers include Entropy, Solvation shell, conformation.
Enzyme reduces the entropy, to hold the substrate in correct orientation to react.
Enzymes plays a role in desolvation, ie.., all the biomolecules in the biological system are surrounded by aqueous solution, Enzymes reduces the hydrogen bonded water molecules, to ensure reaction to take place.
Enzymes alter the conformation of the reactants, from inactive to active form, to expose the reactive functional groups.

2)Enzymes never alter the equilibrium of reaction.