In the stomach and the intestines, food is broken down into more basic elements, including a type of sugar, glucose. The pancreas reacts to sugar by producing insulin, which helps the sugar pass into the body cells.
Kuņģī un zarnu traktā uzturvielas sašķeļas vienkāršākos savienojumos, kuru vidū ir arī glikoze — viens no cukuriem.