Give information regarding the structural organization and functions of polysaccharides.

(N/A) $\rightarrow$ The acid-insoluble pellet also contains polysaccharides (carbohydrates) as another class of macromolecules.
$\rightarrow$ Polysaccharides are long chains of sugars. They are threads (literally a cotton thread) containing different monosaccharides as building blocks.
$\rightarrow$ Cellulose is a polymeric polysaccharide consisting of only one type of monosaccharide, i.e., glucose. Cellulose is a homopolymer.
$\rightarrow$ Starch is a variant of cellulose but is present as a storehouse of energy in plant tissues.
$\rightarrow$ Animals have another polysaccharide called glycogen.
$\rightarrow$ Inulin is a polymer of fructose.
$\rightarrow$ In a polysaccharide chain (e.g., glycogen), the right end is called the reducing end, and the left end is called the non-reducing end.
$\rightarrow$ Starch forms helical secondary structures. Starch can hold $I_2$ molecules in the helical portion. The starch-$I_2$ complex is blue in colour.
$\rightarrow$ Cellulose does not contain complex helices and hence cannot hold $I_2$.
$\rightarrow$ Plant cell walls are made of cellulose. Paper made from plant pulp and cotton fibre is cellulosic.
$\rightarrow$ There are more complex polysaccharides in nature. They have amino-sugars and chemically modified sugars (e.g., glucosamine, $N$-acetyl galactosamine, etc.) as building blocks.
$\rightarrow$ Exoskeletons of arthropods have a complex polysaccharide called chitin. These complex polysaccharides are heteropolymers.