Fructose is an abundant sugar in the human diet; sucrose (table sugar) is a disaccharide that when hydrolyzed yields glucose and fructose and fructose is also a major sugar in honey and fruits. There are two pathways for the metabolism of fructose; one happens in muscle and adipose tissue and the other in liver.

1.  In adipose and muscle tissue, fructose can be phosphorylated by hexokinase (that is capable of phosphorylating both glucose and fructose) to form fructose 6-phosphate that then enters glycolysis.

2.  In liver, the cells hold mainly glucokinase instead of hexokinase and this enzyme phosphorylates only glucose.  Thus in liver, fructose is metabolized instead through the fructose 1-phosphate pathway.

-   Fructose is transformed to fructose 1-phosphate by fructokinase.

-   Fructose 1-phosphate is then change into glyceraldehyde and dihydroxyacetone   phosphate   through   fructose   1-phosphate    aldolase.   The   dihydroxyacetone will feeds into glycolysis   at the triose   phosphate   isomerase   step.