Sucrose (cane sugar), lactose (milk sugar) and maltose are disaccharides in which two monosaccharides are hold together by a glycosidic linkage. (A) In sucrose, C1 of α−D− glucose and C2 of β−D− fructose are linked together (ii). (B) In lactose, C1 of β - D-galactose and C4 of β-D-glucose are linked together (i). (C) In maltose, C1 of α− D-glucose is linked to C4 of another α−D− glucose unit (iii).