During digestion, large molecules must be broken back down into small molecules. Starch must be broken down to glucose. Enzymes produced by the salivary glands and the pancreas carry out this reaction in the mouth and stomach. One particular such enzyme is amylase. By the time food reaches the small intestine where nutrients are absorbed, glucose on its own must be made available for absorption in the epithelial cells lining the intestine. This is achieved by maltase, which breaks down… that’s right, maltose, leaving behind single molecules of glucose.