Describe how carbohydrates are broken down.

First the food is broken down into smaller chunks through the process of mastication. This increases the surface area of the food so enzyme activity is more efficient. The salivary gland secretes salivary amylase which hydrolyses starch into smaller molecules called maltose. The bolus moves down the oesophagus due to peristaltic muscle contractions. No carbohydrate digestion occurs in the stomach due to the high acidity. The bolus proceeds to the small intestine where maltase breaks down the maltose into glucose. Bile from the gallbladder neutralises the stomach acid in the small intestine. The glucose is now small enough to diffuse into the bloodstream.