Biomolecules Part 2

Concept:Sucrose is a disaccharide that undergoes acidic hydrolysis to yield glucose and fructose.Each sugar exhibits a specific optical rotation, and the net rotation of the mixture determines the overall optical activity.Explanation:Sucrose has specific rotation $[\alpha]_D^{\text{sucrose}} = +66.5^\circ$, so it is dextrorotatory.Upon complete hydrolysis, one molecule each of glucose and fructose are produced:• Glucose: $[\alpha]_D^{\text{glucose}} = +52.5^\circ$ (dextrorotatory)• Fructose: $[\alpha]_D^{\text{fructose}} = -92.4^\circ$ (laevorotatory)The net rotation of the equimolar mixture is $(+52.5^\circ) + (-92.4^\circ) = -39.9^\circ$, which is laevorotatory.Therefore, Statement I is correct: the hydrolysis mixture shows laevorotation even though sucrose itself is dextrorotatory.Statement II is incorrect: glucose is dextrorotatory, not laevorotatory. The mixture becomes laevorotatory because the laevorotation of fructose outweighs the dextrorotation of glucose, not because glucose is laevorotatory.Answer:C. Statement I is true but Statement II is false