Answer. Both of these sugars are monosaccharide hexoses. Glucose is a pentahydroxy aldehyde while fructose is pentahydroxy ketone having the open chain structures.
CHO CH2OH
H-C-OH C=O
HO-C H HO-C-H
H-C-OH H-C-OH
H-C-OH H-C-OH
CH2OH CH2OH
Glucose Fructose