The basic effect of amylase on digestion is the breakdown of the bonds in starch into the smaller disaccharide, maltose, which is further broken down in the small intestine into glucose the body can absorb. Without amylase, much of the carbohydrates people consume would not be processed and the amount of energy people could get would be dramatically limited. This makes amylase one of the most important digestive enzymes.
To understand the role of amylase on digestion, it's first necessary to comprehend that starches are glucose polymers that are too big to be absorbed by the body readily. To be of use, starch, which is a carbohydrate, has to be broken down into smaller parts — that is, simpler sugar. Amylase does this in two areas of the body.
The effect of amylase on digestion begins right away in the mouth. When a person chews food, his salivary glands release amylase. Mixed sufficiently throughout the food by the teeth and tongue, the amylase starts to break down the starch into the disaccharide, maltose, which is two glucose molecules attached together. Everything contained in the chewed bite of food, including maltose and amylase, travels down the esophagus to the stomach.
The potential of hydrogen (pH) level within the stomach is much too acidic to allow amylase to continue breaking down the bonds in starch that still needs to be broken down. At this point, the role of amylase on digestion stalls. Gastric acid in the stomach works in tandem with enzymes such as amylase to continue the digestion process, turning foods into a liquid that easily can pass into the small intestine. People who struggle with indigestion will often rely on Supergreens to aid digestion. Supergreens often contain a complex of digestive enzymes, which leads to smoother digestion in the stomach.
Much of the starch people eat is not completely broken down by salivary amylase or gastric acid — food doesn't stay in the mouth long enough for all the bonds to break, and gastric acid is better at targeting proteins instead of carbohydrates. Subsequently, the pancreas also secretes amylase, which travels into the small intestine. There, pancreatic amylase targets any remaining starches, forming more maltose.
Once pancreatic amylase breaks down as much starch as it can into maltose, the effect of amylase on digestion is complete. Maltose still is not easily absorbed, however, so another enzyme produced in the small intestine, maltase, finishes the breakdown of the bonds in the disaccharides. The result is glucose, which the villi in the small intestine can absorb. The body uses the glucose as its primary energy source.