What causes glucose malabsorption?
Glucose-galactose malabsorption (GGM) is an inherited metabolic disorder. It is caused by the small intestines not being able to absorb and use glucose and galactose (simple sugars). Glucose and galactose have very similar chemical structures. The same protein carries both sugars into the intestines.
What is glucose-galactose?
Galactose is a monosaccharide and has the same chemical formula as glucose, i.e., C6H12O6. It is similar to glucose in its structure, differing only in the position of one hydroxyl group. This difference, however, gives galactose different chemical and biochemical properties to glucose.
What does glucose and galactose make?
Galactose is a monosaccharide. When combined with glucose (another monosaccharide) through a condensation reaction, the result is a disaccharide called lactose. The hydrolysis of lactose to glucose and galactose is catalyzed by the enzymes lactase and β-galactosidase.
What’s the difference between glucose and galactose?
Glucose and galactose are both simple structures made of a six-carbon ring. They are almost identical, but galactose differs slightly in the orientation of functional groups around the fourth carbon. Galactose has a higher melting point than glucose as a result of the structural differences.
What causes galactosemia?
Mutations in the GALT, GALK1, and GALE genes cause galactosemia. These genes provide instructions for making enzymes that are essential for processing galactose obtained from the diet. These enzymes break down galactose into another simple sugar, glucose, and other molecules that the body can store or use for energy.
Who discovered glucose-galactose malabsorption?
Maldigestion and Malabsorption Glucose-galactose malabsorption was first described in 1962 by Lindquist and Meeuwisse52 and was subsequently shown to be due to the lack of the sodium-coupled transporter SGLT1 (see Fig. 31.1).
Where is galactose metabolism?
Galactose metabolism takes place primarily in the cytoplasm of cells of the liver. Substrate: Galactose (which is derived from breakdown of lactose in small intestine).
Why is galactose metabolism?
Galactose is crucial for human metabolism, with an established role in energy delivery and galactosylation of complex molecules. Its main metabolic pathway is highly conserved in nature, being present in all living organisms. In humans, galactose is particularly important in early development.
What is the function of galactose in the body?
Galactose serves as a substrate for cerebrosides, gangliosides and mucoproteins in the brain and nervous system, which supports its neural and immunological role [2,3,6,7]. Sources of galactose are not limited only to lactose-containing foods.
What is the relationship between glucose and galactose?
Glucose and galactose are stereoisomers (have atoms bonded together in the same order, but differently arranged in space). They differ in their stereochemistry at carbon 4. Fructose is a structural isomer of glucose and galactose (has the same atoms, but bonded together in a different order).
What is glucose and galactose used for in the body?
Glucose and galactose are simple sugars; they are present in many foods, or they can be obtained from the breakdown of lactose or other sugars and carbohydrates in the diet during digestion. In the intestinal tract, the SGLT1 protein helps the body absorb glucose and galactose from the diet so the body can use them.
How is galactose metabolized in the body?
Galactose is metabolized by means of the Leloir pathway, which allows it to undergo either gluconeogenesis or glycolysis. The initial step in this pathway is the conversion of β-d-galactose to α-d-galactose by mutarotase.