Sugar ‘X’A. is found in honey.B. is a keto sugar.C. exists in α and β – anomeric forms.D. is laevorotatory.‘X’ is

Answer

Composition and Properties of Natural Honey

• Natural honey contains equal amounts of D-glucose and D-fructose.
• D-fructose is a ketohexose, which means it is a six-carbon sugar with a ketone group (a keto-sugar).
• In aqueous solution, D-fructose undergoes cyclization to form:
  • Fructofuranose (5-membered ring)
  • Fructopyranose (6-membered ring)
• These cyclic forms exist as anomeric pairs:
  • α (alpha) anomer
  • β (beta) anomer
• The specific rotation of D-fructose is –92°, making it laevorotatory (rotates plane-polarized light to the left).

Key Terms

• Ketohexose: A monosaccharide with six carbon atoms and a ketone group.
• Anomers: Isomers that differ in configuration around the anomeric carbon in a cyclic sugar.
• Laevorotatory: A compound that rotates plane-polarized light counterclockwise (to the left).