Anomers are those stereoisomers which differ in the configuration at

In aldoses (e.g., glucose) the two anomers (α- and β-glucose) differ in configuration at C1 (carbon having – CHO group), while in ketoses (e. g. fructose) the two anomers differ at C2 (carbon having carbonyl, keto group). Such carbon (– CHO in aldoses which is C1; and > C = O in ketoses which is C2) reacts with the -OH group present at another carbon atom to form glycosides, also known as anomers. Thus C, in aldoses and C, in ketoses constitute the anomeric or glycosidic carbon.