Final answer:
Pectins are long unbranched polymers that form the matrix in which cellulose microfibrils are embedded. They also bind adjacent cell walls together and have a gel-like consistency.
Step-by-step explanation:
Pectins are long unbranched polymers that form the matrix in which cellulose microfibrils are embedded. They also bind adjacent cell walls together and have a gel-like consistency. However, pectins do not trap and bind water molecules. The water-absorbing property of cell walls is primarily due to hemicellulose and other carbohydrate components.