Sucrose, also called table sugar, is a disaccharide consisting of one molecule of glucose linked with one molecule of fructose. Glucose has a chemical composition identical to that of fructose, but the atoms are arranged differently. Dietary sucrose is broken down into glucose plus fructose by an enzyme called sucrase present in the walls of your small intestine, and the two sugars are absorbed into your blood. An increase in blood glucose stimulates insulin secretion from your pancreas to facilitate glucose transport into your tissues, whereas fructose in your blood does not tend to stimulate pancreatic insulin production.