Which monosaccharide has the same number of carbon atoms as glucose but a different functional group?
Fructose is a ketohexose with 6 carbons like glucose (an aldohexose), but it has a ketone group instead of an aldehyde.
Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Carbohydrates - Monosaccharides - Structure and Properties