Abstract:
from the Greek word saccharon meaning sugar.3 Carbohydrates that cannot be
hydrolyzed into simpler compounds are called “monosaccharides” such as glucose,
fructose etc. and a carbohydrate that can be hydrolyzed to two monosaccharides is
called a disaccharide. e.g., sucrose, maltose, lactose, melibiose, cellobiose etc. while
those composed of many monosaccharide units are called polysaccharides.
Carbohydrates with an aldehydic group are known as “aldoses” and those with a
ketonic functionality are “ketoses”. Depending upon the number of carbon atoms it
contains, the monosaccharide is termed as tetrose, pentose, hexose and so on.
Polysaccharides can also be classified4-6 into homopolysaccharide and
heteropolysaccharide depending on the monosaccharide units present. The
carbohydrates those containing only one type of monosaccharide units are called
homopolysaccharides e.g. glucans, mannans, galactans, arabinans etc. whereas
heteropolysaccharides contain two or more different monosaccharide units, e.g.
glucomannans, galactomannans, arabinogalactans etc. Depending upon their
functional property, polysaccharides can be divided into two parts. One is fibrous
polysaccharide, e.g. cellulose in higher plants and some algae, chitin in yeast and
fungi. The other one is the polysaccharide having matrix forming property and is
characterized by their gel forming characteristics which confer flexibility on the
structural assembly. Arabinoxylans, galactomannans of plant origin represent this
group.
