The important properties of enzymes are: 

1. All enzymes are proteins. They are complex macromolecules with high molecular weight.

2.  They catalyse biochemical reactions in a cell. They help in the breakdown of large molecules into smaller molecules or bring together two smaller molecules to form a larger molecule.

3. They catalyse reactions at a high rate with the help of the active site. They lower down the activation energy and thus the reaction can proceed with ease. 

4.  Enzymes do not initiate a reaction but accelerate it. 

5. They are not used up in the reaction. 

6. Enzymes affect the rate and not the direction.

7. Most of the enzymes have a high turnover number that is the number of molecules of a substance that is acted upon by an enzyme per minute. 

8. Enzymes are specific in action.

9. Enzymatic activity is affected by changes in temperature, pH and concentration of the substrate.