The boy physically digests the bread by chewing and grinding the bread into smaller pieces using his teeth. Chemical digestion also occurs as bread is starch salary amylase is the enzyme that digests starch to maltose (smaller sugars). The stomach then change the food, hydrochloric acid is used to kill any bacteria from the bread. Fibre is moved across the body by a process called peristalsis (muscular contractio) along the gut (intestines/stomach). The remaining starch is absorbed by the small intestine.
