Involved in cytoplasmic streaming . Cellular Surfaces and Junctions. A. Cell wall 1. Does not occur in animal cells. Composed of cellulose and pectin.
All plant cells contain a primary cell wall.
Older plant cells lay down a secondary cell wall that contains lignin and is very ridged and strong. Only in animal cells 2. Functions in support, adhesion, movement, and regulation 3. Composed mostly of glycoproteins secreted by the cell. Forms strong fibers.