Table 4: General properties of certain natural polymers [67].

PolymerIncidencePhysiological Functions

        (A) Protein

SilkSynthesized by anthropodsProtective cocoon
KeratinHairThermal insulation
CollagenConnective tissues (tendon, skin)Mechanical support
GelatinPartly amorphous collagenIndustrial product
FibrinogenBloodBlood clotting
ElastinNeck ligamentMechanical support
ActinMusclesContraction motility
MyosinMusclesContraction motility

        (B) Polysaccharides

CellulosePlantsMechanical support
AmylosePlantsEnergy reservoir
DextranSynthesized by bacteriaMatrix for growth of organism
ChitinInsects and CrustaceansProvides shape and form
GlycosaminoglycansConnective tissuesContribution to mechanical support

       (C) Polynucleotides

Deoxyribonucleic acids (DNA)Cell nucleusDirect protein biosynthesis
Ribonuclei acids (DNA)Cell nucleusDirect protein biosynthesis