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lactose


n.

The main sugar present in milk, called also sugar of milk or milk sugar . When isolated pure it is obtained crystalline; it is separable from the whey by evaporation and crystallization. It is a disaccharide with the formula C12H22O11 , being chemically 4-(β-D-galactosido)-D-glucose . It has a slightly sweet taste, is dextrorotary, and is much less soluble in water than either cane sugar or glucose. Formerly called lactin . When hydrolyzed it yields glucose and galactose. In cells it may be hydrolyzed by the enzyme β-galactosidase.


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