Plant Cell Wall Structure

Plant Cell Wall Structure

• The plant cell wall is multi-layered, consisting of up to three sections: middle lamella, primary cell wall, and secondary cell wall.
• Not all plant cells have a secondary cell wall, but all have a middle lamella and primary cell wall.

Middle Lamella

• Outermost layer of the cell wall, containing polysaccharides called pectins.
• Pectins aid in cell adhesion by binding cell walls of adjacent cells together.

Primary Cell Wall

• Layer formed between the middle lamella and plasma membrane in growing plant cells.
• Primarily composed of cellulose microfibrils, hemicellulose fibers, and pectin polysaccharides.
• Provides strength and flexibility needed for cell growth.

Secondary Cell Wall

• Layer formed between the primary cell wall and plasma membrane in some plant cells.
• Forms after primary cell wall has stopped dividing and growing, and thickens to provide strength and support.
• Composed of cellulose, hemicellulose, and sometimes lignin, which strengthens the cell wall and aids in water conductivity in plant vascular tissue cells.