The key functional groups present in a typical carbohydrates are the
hydroxyl group (-OH) and the
carbonyl group (>C=O) made up of the ketone group (>C=O) or the aldehyde group (-HC=O). An hydroxyl group (-OH) is bonded to all carbon atoms in the monosaccharide except one. That carbon is double bonded to an oxygen atom, forming a carbonyl group.
