Bonds in cellulose that make it resistant to digestion is:
Cellulose is the chief constituent of plant cell walls. It is insoluble and consists of b-D -glucopyranose units linked by b,1-4 bonds to form long, straight chains strengthened by cross-linking hydrogen bonds. Mammals lack any enzyme that hydrolyzes the b1 -4 bonds, and so cannot digest cellulose. Ref: Harper 28th edition, chapter 14.
b1-4
a1-6
b1-6
a1-6