BIOC12H3 Lecture Notes - Lecture 11: Peptidoglycan, Threonine, Cellobiose
Document Summary
Carbohydrates can be described by the number of monomeric units they contain. Monosaccharides are the smallest units of carbohydrate structure. Oligosaccharides are polymers of two to about 20 monosaccharide residues. The most common oligosaccharides are disaccharides, which consist of two linked monosaccharide residues. Polysaccharides are polymers that contain many (usually more than 20) monosaccharide residues. Oligosaccharides and polysaccharides do not have the empirical formula (ch2o)n because water is eliminated during polymer formation. The term glycan is a more general term for carbohydrate polymers. It can refer to a polymer of identical sugars (homoglycan) or of different sugars (heteroglycan). Monosaccharides are water-soluble, white, crystalline solids that have a sweet taste. Chemically, monosaccharides are polyhydroxy aldehydes, or aldoses, or polyhydroxy ketones, or ketoses. They are classified by their type of carbonyl group and their number of carbon atoms. As a rule, the suffix -ose is used in naming carbohydrates, although there are a number of exceptions.