Basque PAU Biology Practice Questions - Basque Country PAU Biology Examination - UPV EHU (2o Bachillerato 2026) Exam

An aldose cannot form D and L enantiomeric isomers, whereas a ketose can. An aldose has carboxylic acid groups, whereas a ketose contains ester linkages. An aldose forms ring structures with five atoms, whereas a ketose forms rings with seven atoms. An aldose contains a carbonyl group at carbon-1 (aldehyde), whereas a ketose contains a carbonyl at carbon-2 (ketone).