See image — Biomolecules Chemistry Question

💡 Solution & Explanation

Concept: Mutarotation is the phenomenon observed in reducing sugars where the optical rotation of a solution changes over time due to interconversion between anomeric forms. Reasoning: When α-D-glucose or β-D-glucose is dissolved in water, the cyclic hemiacetal ring can open to form the open-chain aldehyde form, which can then reclose to give either the α or β anomer. This equilibration between α-D-glucose and β-D-glucose results in a change (and eventual stabilization) of optical rotation. This process is specifically termed mutarotation. Why other options fail: (a) Racemization refers to the conversion of an optically active compound into a racemic mixture (equal amounts of enantiomers), which is not what is happening here — both α and β forms are still D-glucose, not a mixture of D and L. (b) Asymmetric induction refers to the preferential formation of one stereoisomer over another in a reaction due to a chiral influence, which is unrelated to anomeric interconversion. (c) Fluxional isomerization refers to rapid interconversion of structural or conformational isomers in organometallic or other contexts, not the anomerization of sugars. Therefore, the correct answer is D.