Fibronectin serves what primary function in animal cells?

Fibronectin plays a crucial role in providing structural support to animal cells by facilitating their attachment to the extracellular matrix (ECM). The extracellular matrix is a complex network of proteins and carbohydrates that support cell adhesion, differentiation, and tissue formation. Fibronectin acts as a bridge between cells and the ECM, allowing cells to adhere effectively, which is essential for tissue integrity and proper cellular communication.

When cells attach to the ECM, it promotes various cellular processes such as migration, growth, and healing. The interaction between fibronectin and cell surface receptors, specifically integrins, is vital for maintaining tissue architecture. This anchoring mechanism is critical in processes like wound healing, embryogenesis, and maintaining tissue homeostasis.

The other options do not accurately reflect the primary function of fibronectin in animal cells. For instance, fibronectin is not involved in energy storage, oxygen transport, or muscle contraction, which are functions carried out by other biomolecules and structures within the body.