Any monosaccharide with the carbonyl (CO) group on the terminal carbon, so forming an aldehyde (CHO) group. The simplest aldose is the three-carbon sugar *glyceraldehyde
. Other aldoses include glucose, galactose, and mannose, which are aldohexoses, and ribose, arabinose, and xylose, which are aldopentoses (see diagram). Compare ketose
Some common aldoses.