Fructose-1-phosphate is a derivative of

fructose Fructose, or fruit sugar, is a Ketose, ketonic monosaccharide, simple sugar found in many plants, where it is often bonded to glucose to form the disaccharide sucrose. It is one of the three dietary monosaccharides, along with glucose and galacto ...

. It is generated mainly by

hepatic fructokinase Hepatic fructokinase (or ketohexokinase) is an enzyme that catalyzes the phosphorylation of fructose to produce fructose-1-phosphate Fructose-1-phosphate is a derivative of fructose. It is generated mainly by hepatic fructokinase but is also g ...

but is also generated in smaller amounts in the small intestinal mucosa and proximal epithelium of the renal tubule. It is an important intermediate of glucose metabolism. Because fructokinase has a high Vmax fructose entering cells is quickly phosphorylated to fructose 1-phosphate."Marks A. Basic Medical Biochemistry: a clinical approach, 3rd ed. p.540 In this form it is usually accumulated in the liver until it undergoes further conversion by

aldolase B Aldolase B also known as fructose-bisphosphate aldolase B or liver-type aldolase is one of three isoenzymes (A, B, and C) of the class I fructose 1,6-bisphosphate aldolase enzyme (EC 4.1.2.13), and plays a key role in both glycolysis and glucon ...

(the rate limiting enzyme of fructose metabolism). Aldolase B converts it into

glyceraldehyde Glyceraldehyde (glyceral) is a triose monosaccharide with chemical formula C3 H6 O3. It is the simplest of all common aldoses. It is a sweet, colorless, crystalline solid that is an intermediate compound in carbohydrate metabolism. The word comes ...

and

dihydroxyacetone phosphate Dihydroxyacetone phosphate (DHAP, also glycerone phosphate in older texts) is the anion with the formula HOCH2C(O)CH2OPO32-. This anion is involved in many metabolic pathways, including the Calvin cycle in plants and glycolysis.Nelson, D. L.; ...

(DHAP). Glyceraldehyde is then phosphorylated by triose kinase to glyceraldehyde 3-phosphate. Metabolism of fructose thus essentially results in intermediates of

glycolysis Glycolysis is the metabolic pathway that converts glucose () into pyruvate (). The free energy released in this process is used to form the high-energy molecules adenosine triphosphate (ATP) and reduced nicotinamide adenine dinucleotide (NADH ...

. This means that fructose has the same fate as glucose after it gets metabolised. The final product of glycolysis (pyruvate) may then undergo

gluconeogenesis Gluconeogenesis (GNG) is a metabolic pathway that results in the generation of glucose from certain non-carbohydrate carbon substrates. It is a ubiquitous process, present in plants, animals, fungi, bacteria, and other microorganisms. In vertebrat ...

, enter the

TCA cycle The citric acid cycle (CAC)—also known as the Krebs cycle or the TCA cycle (tricarboxylic acid cycle)—is a series of chemical reactions to release stored energy through the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins ...

or be stored as fatty acids.

Clinical significance

hereditary fructose intolerance Hereditary fructose intolerance (HFI) is an inborn error of fructose metabolism caused by a deficiency of the enzyme aldolase B. Individuals affected with HFI are asymptomatic until they ingest fructose, sucrose, or sorbitol. If fructose is ing ...

caused by defects in aldolase B, fructose 1-phosphate accumulates in the liver and causes a number of adverse defects. Hypoglycemia results from inhibition of glycogenolysis and gluconeogenesis. It depletes intracellular phosphate reserves which leads to loss of ATP and inhibition of biosynthetic pathways. Symptoms of hereditary fructose intolerance are apathy, drowsiness, sweatiness and tremulousness.

References

{{DEFAULTSORT:Fructosephosphate1 Monosaccharide derivatives Organophosphates