Classify each monosaccharide by the type of carbonyl group and the number of carbons in the chain.
Identify the type of carbonyl group to label the monosaccharide as an aldose or ketose. An aldose has the C\overline{—}O at C1 so that a hydrogen atom is bonded to the carbonyl carbon. A ketose has two carbons bonded to the carbonyl carbon. Count the number of carbons in the chain to determine the suffix—namely, -triose, -tetrose, and so forth.
