Enzymes are a protein serving as a catalyst, a chemical agent that changes the rate of the reaction without being consumed by the reaction.
Usually the active site is formed by only a few of the enzyme's amino acids, the rest is just the framework that reinforces the active site. In an enzymatic reaction, the substrate enters the active site then is held in place by weak bonds. Now the enzyme does its work and first changes shape so it can hold onto the substrate. Next the substrate is changed to its product, the product is released and the enzymes active site is ready and waiting for another molecule of substrate.
Amylase is an enzyme in human saliva and in other organisms and its substrate is starch. When the active site of amylase binds with the starch, hydrolysis takes place. When the hydrolysis (the breaking of a chemical bond with the insertion of the ions of a water molecule) of starch is complete...