We consume complex food, and in order for it to be absorbed from the alimentary canal, it must be broken down into smaller molecules. Enzymes, which are biological catalysts, are usually used in this procedure. The complex molecule starch is broken down by an enzyme called salivary amylase in the saliva to produce sugar. Saliva is used to fully mix the food as it is moved around the mouth and chewed by the powerful tongue. Therefore, saliva is essential for food digestion and absorption.