Here's why:
* Cellulose is a complex carbohydrate: It's a long chain of sugar molecules linked together.
* It forms strong fibers: These fibers are arranged in bundles called microfibrils which create a rigid network within plant cell walls.
* This network provides structural support: It allows plants to grow upright, resist bending and breaking, and hold their shape.
* It's also responsible for the strength of wood and other plant tissues.
While other substances like lignin and hemicellulose also contribute to plant structure, cellulose is the primary component.
