Assertion: collagen | /r/ObjectUse | used by plant
Facets:
Source sentences:
text: In nature, these networks self-assemble to generate important structural and functional elements at various length scales: actin, intermediate filaments and microtubules are the main components of the cytoskeleton ; spectrin confers versatile qualities to red blood cell membranes ; fibrin is an essential element in hemostasis ; collagen is the main component of the extracellular matrix (ECM) in the animal kingdom  and cellulose is used by plants to build cell walls .