Cell wall structure and functions .pptx

basic info about topic

1. CELL WALL

2. CELL Cells are the basic building blocks of all living things. The human body is composed of trillions of cells . They provide structure for the body, Take in nutrients from food , C onvert those nutrients into energy , Carry out specialized functions . Cells also contain the body’s hereditary material and can make copies of themselves

3. COMPONENT OF PLANT CELL

4. CELL WALL

5. CELL WALL

6. CELL WALL

7. LAYERS OF CELL WALL

8. CELL WALL STRUCTURE

9. COMPOSITION OF PRIMARY CELL WALL

10. CELLULOSE M ost abundant biomaterials on the earth S ynthesized by plants, but it is also produced by some bacteria Cellulose is synthesized by the enzyme cellulose synthase C ellulose is a homopolymer of glucose G lucose  monomers are joined by β-1,4 linkages

11. CELLULOSE Cellulose chains are arranged in microfibrils or bundles of polysaccharide that are arranged in fibrils (bundles of microfibrils), which in turn make up the plant cell wall Cellulose , a tough, fibrous, and water-insoluble polysaccharide, plays an integral role in keeping the structure of plant cell walls stable .   Cellulose is crystalline, strong, and resistant to hydrolysis,

12. HEMICELLULOSE A  hemicellulose  (also known as  polyose ) is one of a number of  heteropolymer. H emicellulose may be branched  polymers H emicelluloses have random, amorphous structure with little strength . E asily hydrolyzed   Hemicelluloses consist of shorter chains – 500–3,000 sugar units

13. HEMICELLULOSE   Sugar monomers in hemicelluloses can includes   Xylose  and A rabinose   Mannose  and G alactose  D eoxy sugar R hamnose Hemicelluloses contain most of the D-pentose sugars, and occasionally small amounts of L-sugars as well .   Xylose  is in most cases the sugar monomer present in the largest amount,

14. PECTIN Pectin was first isolated and described in 1825 by  Henri Braconnot. P ectin consists of a complex set of polysaccharides P resent in most primary cell walls Are particularly abundant in the non-woody parts of terrestrial plants .

15. PECTIN The main use for pectin is as a gelling agent, thickening agent and stabilizer in food. Galacturonic acid Rhamnose Galactose Arabinose

16. PROTEIN Proteins are often concentrated in specialized cells and in cell corners Protein involved in wall expansion Involved in growth and development

17. Lipids

18. MIDDLE LAMELLA Middle lamella  is the first formed layer, present between the two adjacent cells. It is situated outside the primary cell wall. Outermost layer between adjacent plant cells Contain pectins Made up of Calcium and Magnesium pectates Gives stability (form Plasmodesmata)

19. SECONDARY CELL WALL

20. Secondary cell wall composition

21. Layers of secondary wall It sometimes consists of three distinct layers - S 1 , S 2  and S 3   Secondary cell walls provide additional protection to cells and rigidity and strength to the larger plant.

22. Lignin in secondary wall The lignin monomers arise from the aromatic amino acid phenylalanine and tyrosine. Lignin is Polyphenol that strengthens the wall, makes it water proof and resistant to decay and animals attack by herbivores