Why do we use enzymes more than one time?

Answer 1

Enzymes are catalysts and as such play no direct part in a chemical reaction. Enzymes provide active sites for chemical reactions to take place on. They are specific and work best in a narrow band of optimal conditions.

Catalysts of all sorts have 2 major advantages of a chemical reaction without them:

1. they speed up the chemical reaction dramatically
2. they are reusable

As they are not used up in the reaction new enzymes do not need to be constantly produced which reduces the pressure on resources in the body. It would be wasteful to have to constantly make new enzymes. Similarly in industry it makes economic sense to use catalysts because they can be used over and over.