Enzymes are molecules which increase the rate of specific chemical reactions. They are generally proteins which are essential for life functions such as digestion and metabolism. Some of them are responsible for breaking down large molecules while others assist in combining two molecules. Some of the most common and vital enzymes are amylase, lipase, protease, and cellulase. For instance, amylase is a vital enzyme which breaks down carbohydrates and starch into sugars during digestion.