Question

Which of the following carbohydrates is an aldohexose?

• A. D-Mannose
• B. D-Glucose
• C. D-Fructose
• D. Both (a) and (b)

Answer 1

The correct option is D Both (a) and (b)

In D-mannose and D-glucose both have $6$ carbons and a $-CHO$ group. So, D-mannose and D-glucose both are aldohexose.(prefix-'aldo' for aldehyde functional group and 'hex' for $6C$ in the chain).


But fructose has ketone functional group with $6C$ in the chain. So, it is called ketohexose.
Hence, (d) is correct.