How do cellulose microfibrils give the plant cell wall its tensile strength?
A.
Like all extracellular matrices, plant cell walls derive their tensile strength from long fibers oriented along the lines of stress.
B.
In higher plants, the long fibers are generally made from the polysaccharide cellulose, the most abundant organic macromolecule on Earth.
C.
These cellulose microfibrils are interwoven with other polysaccharides and some structural proteins, all bonded together to form a complex structure that resists both compression and tension.
D.
Other polysaccharides cross-link the cellulose microfibrils, while the polysaccharide pectin fills the spaces between the microfibrils, providing resistance to compression. The middle lamella is rich in pectin and is the layer that cements one cell wall to another.