The extracellular matrix (ECM) is a complex network of molecules that surrounds and supports animal cells. It provides structural support, binds cells together, and regulates cellular communication. The ECM is composed of various proteins, carbohydrates, and lipids, including:

* Collagen: The most abundant protein in the ECM, collagen provides tensile strength and elasticity.

* Elastin: A flexible protein that allows tissues to stretch and recoil.

* Fibronectin: A glycoprotein that helps cells attach to the ECM.

* Laminin: A glycoprotein that forms a network beneath the cell membrane and helps cells adhere to the underlying substrate.

* Proteoglycans: A complex of proteins and glycosaminoglycans (GAGs) that provide hydration and lubrication.

* Glycosaminoglycans: Long, unbranched polysaccharides that attract water and create a gel-like environment.

The ECM is essential for the proper function of animal cells. It provides a scaffold for cell migration and growth, regulates cell shape and differentiation, and transmits signals between cells.