Where Does Starch Digestion Begin?

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The digestion of starch begins in the mouth. Saliva contains an enzyme that digests starch before it enters the stomach. This makes the starch easier for the body to metabolize, providing the body with energy just a little bit quicker.

The enzyme is called amylase, and it is secreted while you chew. Amylase breaks starch down into a simpler sugar called maltose. Any amylase absorbed by the starch will continue to act even within the stomach's highly acidic environment for up to 2 hours, although amylase on the surface of the starch will be destroyed. The stomach also contributes some of its own amylase to the digestive mix, via secretions of the enzyme by the pancreas.

Once the starch is broken down into maltose, the maltose is absorbed by the lining of the small intestine. An enzyme called maltase breaks the maltose down further, into two molecules of glucose. Glucose is the basic sugar that the body has the easiest time metabolizing. The glucose produced travels through the lining of the small intestine into the blood, and from there it enters bodily cells which need energy for basic life processes. Any glucose not used immediately is converted into fat for storage.