In polysaccharides, the linkages connecting the monosaccharide units…

Monosaccharides are carbohydrates which cannot be hydrolysed into simpler molecules. Those containing an aldehyde group are called aldoses while those containing a keto group are called ketoses. The aldehyde group is present at C1 while the keto group is usually present at C2. All monosaccharides reduce Tollens’ reagent as well as Fehling’s solution and hence are called reducing sugars. Glucose has a six-membered cyclic structure called the pyranose structure, while fructose in sucrose has a five-membered cyclic structure called the furanose structure. During ring formation, C1 of glucose becomes chiral, and hence glucose exists in two cyclic forms called the α-anomer and the β-anomer. When two molecules of the same or different monosaccharides combine through a glycosidic linkage, a disaccharide is formed.