- A sugar contained in milk. Galactose makes up half of the sugar called lactose that is found in milk. Lactose is called a disaccharide, di meaning 2, since lactose is made up of two sugars, galactose and glucose, bound together. Galactose is metabolized (used) through the action of an enzyme called GALT (galactose-1-phosphate uridyl transferase).
* * *An aldohexose found (in d form) as a constituent of lactose, cerebrosides, gangliosides, mucoproteins, etc., in galactoside or galactosyl combination; an epimer of d-glucose.
* * *ga·lac·tose gə-'lak-.tōs, -.tōz n an optically active sugar C6H12O6 that is less soluble and less sweet than glucose and is known in dextrorotatory, levorotatory, and racemic forms
* * *n.a simple sugar and a constituent of the milk sugar lactose. Galactose is converted to glucose in the liver. The enzyme necessary for this conversion is missing in infants with a rare inherited metabolic disease called galactosaemia.
* * *ga·lac·tose (gə-lakґtōs) [Gr. gala, gen. galaktos milk] an aldohexose epimeric with glucose at the 4 carbon but less soluble and less sweet, occurring naturally in both D- and L- forms (the latter in plants); it is a component of lactose and other oligosaccharides, cerebrosides and gangliosides, and various glycolipids and glycoproteins.
Medical dictionary. 2011.