Basement membranes are thin, dense sheets of specialized, self- assembled extracellular matrix that surround most animal tissues. The basement membrane is a fibrous matrix composed primarily of glycoproteins, type IV collagen, and laminin that are secreted by the epithelial cells.
Answer:
I agree it would be A) IT is a reactant in a chemical reaction
Explanation:
a catalyst is a substance that causes a chemical reaction to happen in a different way than it would happen without that catalyst
3. cell wall
The cell wall is a rigid supporting structure.