What do enzymes do to chemical reactions in cells?

Enzymes are homogenous, thermolabile,biological catalyst that increases the reaction rate of a chemical reaction.

Explanation:

Enzymes are used as catalyst in many biochemical reactions.Enzymes basically interact in a complementary fashion with the transition state of the reaction thus helping to decrease the energy barrier called activation energy.Thus enzymes helps to stimulate  the velocity of biochemical reaction.

      It is very important point to note that enzymes do not affect the reaction equilibrium.