Question

D–Glucose units joined by beta-1,4’-glycosidic linkages are not digestible by humans. Why not?

Answer 1

In human digestion system alpha amylase enzyme breaks down the alpha glycosidic bond and therefore we digest that type of poly or oligosacharides.But human digestion system lacks enzyme that causes breakdown of beta glycosides,and therefore we can't digest that type of joined poly or oligo sacharides.For example we can't digest cellulose,because it has 1,4-beta glycosidic linkage of glucose,and in our body,lacks of cellulase (enzyme,which causes breakdown of that kind of linkage) and therefore we can't digest cellulose,but in some animal body,for example in cow's body that enzyme present and so they digest cellulose.