What is a Cell Wall?

A plant cell wall is a structure surrounding the cell that provides a number of functions:  

• Strength to support the plant
• Rigidity to fix cell shape
• Flexibility
• Porosity
• Water-proofing
• Barrier to pests
• Protection against environmental stress 
• Apoplastic transport
• Signalling and sensing             

Plant cell walls are a complex mixture of cellulose and non-cellulosic polysaccharides (sugars), proteins, lignin and water.

Primary cell walls are found in young growing tissue

Secondary (thickened) cell walls are found in tissue that has stopped growing