polysaccharide Chem.
(pɒlɪˈsækəraɪd)
Formerly also -id.
[ad. G. polysaccharid (B. Tollens Kurzes Handbuch d. Kohlenhydrate (1888) 16), f. poly- + saccharid saccharide.]
Any carbohydrate whose molecules consist of a number of monosaccharide residues (or their simple derivatives) bonded together, usu. in a chain structure, and esp. one of high molecular weight; also applied to such a structure which forms part of a larger molecule.
| 1892 E. F. Smith tr. V. von Richter's Org. Chem. (ed. 2) 512 It is very probable that the polysaccharides having the empirical formula C6H10O5, really possess a much higher molecular weight, (C6H10O5)n. 1895 Jrnl. Chem. Soc. LXVIII. ii. 322 It appears probable that the fermentation of the polysaccharides by saccharomycetes is preceded by their conversion into monosaccharides through the agency of enzymes. 1902 Encycl. Brit. XXXI. 723/2 By further polymerization and loss of water the group of polysaccharids..is produced. 1947 Endeavour VI. 89/2 Other substances of high molecular weight, such as the polysaccharides, consist mostly of molecules of continuously varying size. 1951 Sci. News XXI. 72 Any carbohydrate, such as glucose, cellulose, cane-sugar, or starch, can be represented by the formula Cn(H2O)m where m is equal, or very nearly equal, to n... For polysaccharides such as starch or cellulose, n and m may run up to hundreds. 1960 New Biol. XXXI. 72 The virulent and avirulent types [of pneumococcus] can be quickly and easily distinguished because the virulent cells are enclosed in a polysaccharide capsule that can be seen under the microscope. 1968 A. White et al. Princ. Biochem. (ed. 4) xli. 910 (caption) Two units from neighboring polysaccharide chains can be bridged by a peptide. 1969 New Scientist 7 Aug. 270/1 Some natural polysaccharides show startlingly similar conformational behaviour to proteins and nucleic acids. 1973 R. G. Krueger et al. Introd. Microbiol. xxiv. 590/2 The major antigenic components of bacteria and their products are polysaccharides of one sort or another. |