How does the structure of a distinctive layer that is used as a marker determine its function

Keratin has two main functions: to adhere cells to each other and to form a protective layer on the outside of the skin. In epithelial cells, keratin proteins inside the cell attach to proteins called desmosomes on the surface. The desmosomes act as anchors, holding the cells together.

Ithink its called the coefficent.

The answer is ax3. hope this