How enzyme catalyze chemical reaction?

Answer 1

Enzymes lower the activation energy of a reaction (that is, the amount of energy that is needed in order for the reaction to occur).
Without an enzyme, a reaction may need so much energy that it is impossible to obtain in a normal biological timespan. With enzymes, reactions require much less energy, so that they can occur hundreds of times a second.
Enzymes can achieve this catalysis in many ways - for instance, if a reaction involves two substances combining to form one, the enzyme can bind each substance in a specific site that forces them close together, making the reaction much more likely to occur and requiring much less energy for the substrates to locate and approach one another.

Answer 2

Enzymes catalyze chemical reactions by speeding up the process without being consumed. They do this by lowering the energy required for the reaction to occur, facilitating the formation of the products from the substrates. Enzymes achieve this by binding to the substrates at their active site and stabilizing the transition state of the reaction.

Answer 3

by positioning substrates and destabilizing bonds

Answer 4

The activation energy of a reaction is lowered by enzyme.