1.2 Carbohydrates can be categorized into monosaccharides. oligosaccharides and polysacchrides. 1.2.1 Monosacchrides are simple sugars consisting of a single polyhydroxyl aldehyde or ketone unit(e.g, glyceraldehyde, dihydroxyacetone, ribose, glucose, galatose, ribulose, and fructose)1.2 Carbohydrates can be categorized into monosaccharides, oligosaccharides, and polysacchrides. 1.2.1 Monosacchrides are simple sugars consisting of a single polyhydroxyl aldehyde or ketone unit (e.g., glyceraldehyde, dihydroxyacetone, ribose, glucose, galatose, ribulose, and fructose)