Enzymes are called Biological catalysts because they diminish the activation energy for reactions. As the activation energy is reduced the rate of reaction is increased.
Many enzymes modify their state when substrates bind and it is known as "Induced fit".
Enzymes are nothing but Protein(Biological molecules). Most of the biological reactions are catalyzed by Protein.
Enzymes improve the rate of synthetic reactions without getting altered forever by the reaction.
For this reason Biological catalyst are needed to be cut and copy segemnte in DNA.
The reason is because it takes a long time for the light from the stars in the sky to reach earth, so the light the star was producing millions of years ago has just now reached Earth.
