Answer to Question #54792 in Biology for Thuy

Question

What's the difference between soluble and insoluble fiber? A lot of details will be helpful.

Answer 1

Chemical properties of the structural units in the macromolecular polymers define whether they can interact with water molecules (soluble fibers) or not (insoluble fibers). For instance, cellulose, a heteropolysacharide constists of monosacharides linked by beta 1-4 glycosidic bonds which make this type of fiber liner and stable. The poperty of using intra and intermolecular bonds to make crystals renders cellulose excessively insoluble in water and aqueous solutions. In contrast to cellulose another biopolymer -pectin- is soluble as among its glucose units it contains an alpha 1,4 glycosidic and an alpha 1,6 glycosidic linkages. Another example is lignin which is a dendritic network polymer of phenyl propene basic units that are hydrophobic and make this type of fiber insoluble.