PowerPoint Presentation On The Cell Wall

PPT On The Cell Wall

Download

The Cell Wall Presentation Transcript:

1. INTRODUCTION
The plant cell wall is a remarkable structure. It provides the most significant difference between plant cells and other eukaryotic cells. The cell wall is rigid (up to many micrometers in thickness) and gives plant cells a very defined shape. While most cells have a outer membrane, none is comparable in strength to the plant cell wall. The cell wall is the reason for the difference between plant and animal cell functions. Because the plant has evolved this rigid structure.

2. On the basis of chemical composition of cell wall there are three types of cell wall: 1) Green Plant Cell Wall : which is made up of Cellulose. 2) Cell Wall of Fungi: made up of Chitin. 3) Bacteria Cell Wall: made up of Mucopeptide and Muramic Acid. The cell wall is composed of Cellulose, fibres, polysaccharides and proteins i.e Living Protoplast. It consist of the following: Middle lamella Primary Cell Wall Secondary Cell Wall Tertiary Cell Wall

3. 1. MIDDLE LAMELLA
It is present between two adjacent cells. It is situated outside primary cell wall and is made up of calcium and magnesium pectate. It acts as cement which holds the adjacent cells together.
2. PRIMARY CELL WALL It is present beneath Middle lamella. It is made up of Cellulose, Hemi-cellulose, pectic substances, lipids, proteins, minerals, elements and water.

4. 3. SECONDARY CELL WALL
It is present beneath Primary Cell wall. It is made up of Cellulose, Hemi-cellulose and polysaccharides. Secondary Cell wall is deposited Lignin.
4. TERTIARY CELL WALL Tertiary Cell wall is deposited in few cells. It is considered to be dry residue of protoplast. Besides Cellulose and Hemi-cellulose, Xylan is also present.

5. On the whole, each cell's cell wall interacts with its neighbours to form a tightly bound plant structure. Despite the rigidity of the cell wall, chemical signals and cellular excretions are allowed to pass between cells.

6. The primary wall of cells are capable of expansion. The middle lamella is formed during cell division and grows coordinately during cell expansion. Contact between certain cells is maintained by the middle lamella , and the cell corners are often filled with pectin rich polysaccharides. In older cells the material in the cell corners is sometimes degraded and an air space formes.

7. Plant cell walls
Are made of cellulose fibers embedded in other polysaccharides and protein May have multiple layers

8. Cell Wall components
Cellulose Other carbohydrates Lignin (other polyphenolics) Proteins

9. Carbohydrates
Classified by solubilities Pectins – complex carbohydrates extracted in water using Calcium chelators Polyuronic acids Arabinans Glactans Hemicelluloses – soluble in 4M KOH Xylans - common Mannans – abundant in conifers Arabinoglactans Microfibrillar components Cellulose Beta 1,4 mannans - algae Beta 1,3 xylans - algae

10. For more please refer our PPT. Thanks.