Final answer:
Carbohydrate digestion starts in the mouth with salivary amylase and continues in the small intestine with pancreatic amylase, producing monosaccharides like glucose, fructose, and galactose, which are the absorbable units of carbs.
Step-by-step explanation:
Process of Digestion of Carbohydrates
The digestion of carbohydrates begins in the mouth with the action of the enzyme salivary amylase, which starts breaking down starches into simpler sugars such as maltose. As food passes through the esophagus to the stomach, the acidic environment causes the amylase to become inactive. Digestion then continues in the small intestine, where pancreatic amylase further breaks down the dextrins into monosaccharides. The primary absorbable units of carbohydrates, being glucose, fructose, and galactose, are then absorbed through the epithelium of the small intestine into the bloodstream.
Complex carbohydrates such as starches, polysaccharides, and disaccharides must be reduced to simple monosaccharides before they can be absorbed. These simple sugars are then transported to tissues where they undergo cellular respiration and are used to produce energy in the form of ATP. Therefore, the absorbable units of carbohydrates are these monosaccharides.