Question

The term anomers of glucose refers to
(a) isomers of glucose that differ in configurations at carbons one and four (C -1 and C - 4)
(b) a mixture of (D) - glucose and (L)glucose
(c) enantiomers of glucose
(d) isomers of glucose that differ in configuration at carbon one (C - 1).

Answer 1

 (d) : Due to cyclic hemiacetal or cyclic hemiketal structures, all the pentoses and hexoses exist in two stereoisomeric forms i.e. α form in which the OH at C₁ in aldoses and C₂ in ketoses lies towards the right and β form in which it lies towards left. Thus glucose, fructose, ribose, etc., all exist in α and β form. Glucose exists in two forms α-Dglucose and β-D glucose. 

α-D(+) glucose ⇋ equilibrium mixture ⇋ β-( D)(+) glucose

 As a result of cyclization the anomeric (C -1) becomes asymmetric and the newly formed – OH group may be either on left or on right in Fischer projection thus resulting in the formation of two isomers (anomers). The isomers having – OH group to the left of the C -1 is designated β-Dglucose and other having – OH group on the right as α-Dglucose.