BIOL107 Chapter Notes - Chapter 6: Cell Wall, Middle Lamella, Primary Cell

• School: University of Alberta
• Department: Biology (Biological Sciences)
• Course: BIOL107
• Professor: Kirstin Veugelers

Document Summary

Extracellular structure of plant cells that distinguishes them from animal cells. Protects the cell, provides shape and structure and prevents excessive uptake of water. Made up of micro fibrils that are composed of cellulose. They are synthesized by cellulose synthase and secreted into the extracellular space where they become embedded in a matrix of other polysaccharides and protein. A young plant first has a primary cell wall (thin and flexible). Between the primary cell walls of adjacent cells is the middle lamella, a thin layer rich in sticky polysaccharides called pectins. Once the cell is mature, it strengthens the cell wall by secreting hardening substances into the primary wall or by adding a secondary cell wall between the plasma membrane and primary cell wall. The main ingredient of the ecm are glycoproteins and other carb-containing molecules. Most abundant glycoprotein in the ecm is collagen which forms strong fibers outside of the cell.