What Does Fructose Consist Of?

Fructose is a carbohydrate that gives many foods their sweet flavors. It is also a monosaccharide or a simple sugar. Combined with glucose, it forms the disaccharide, sucrose, also known as table sugar. It can be purchased in the supermarket as crystalline fructose and in high-fructose corn syrup.

Fructose the Molecule

• Fructose also occurs in honey.

  Fructose is a naturally occurring simple sugar found in fruits and honey. Glucose, fructose and galactose are isomers of each other. That means they have the same molecular formula C6H12O6. In other words, they have 6 carbons, 12 hydrogens and 6 oxygens. They have a molecular weight of 180 atomic mass units (amu), but they differ in their molecular structure.

Fructose Structure

• Fructose has a pentagon shape similar to these objects.

  While glucose and galactose form a six-carbon ring, fructose forms a five-carbon ring. It is shaped like a pentagon. Because of the structural differences the body metabolizes the molecules differently. For instance the body needs insulin to use glucose, but not fructose. Also, glucose feeds the brain, but the brain cannot use fructose.

Dietary Considerations

• The chemical structure of glucose and galactose form a hexagon.

  Food producers started adding high-fructose corn syrup to food products in the 1970s. According to the Mayo Clinic and the Diabetes Health website, the increased use of fructose in the diet has negative implications for weight gain and diabetes. A study in "Cancer Research" in August 2010 showed pancreatic cancer cells thrived on fructose. The researchers believe this finding could help control cancer through regulation of dietary intake of fructose.