Biomolecules

On treatment with HNO₃, gluconic acid is oxidized to saccharic acid, whereas glucose is not oxidized to saccharic acid.

Fructose gives a positive Fehling’s test because it isomerises to glucose and another aldohexose in the presence of Fehling’s reagent.

Invert sugar is an equimolar mixture of D-glucose and D-fructose formed after hydrolysis of the corresponding disaccharide.

Specific rotation of invert sugar is −40°.