Cellulose is found throughout the cell walls of plant cells. cellulose makes cell walls rigid. why does it make the walls rigid?

Because it forms beta arrangements subsecuently forming microfibrils

Explanation:

Cellulose is a complex carbohydrate formed by a long polysaccharide of glucose molecules with beta arrangements, these give a flat and rigid structure that held to each other through hydrogen bonds forming microfibrils that give their rigidity to the cell walls (you can see this structure in the image added).

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