Chemical composition of cell wall
Chemical composition of cell wall
The cell wall is mainly composed of carbohydrate rich materials. The major components of cell wall are cellulose, pectins, hemicelluloses, proteins and phenolics.
1)Pectic acid-
*It is the major component of the middle lamella but is also found in the primary walls.
*Pectic acid is the polymer of about 100 galacturonic acid molecules.
* It is hydrophilic in nature.
* It forms salt bridges with calcium and magnesium ions.
2)Pectin:
*It is the another major component of the middle lamella but is also found in the primary walls.
*It is a polymer of around 200 galacturonic acid molecules.
*Compared to pectic acid it is less hydrated. It is soluble in hot water.
3) cellulose-
*glucose polymer is the main chemical component of cell wall
*Glucose molicule are attached with polysaccharide by β1,4 glycosidic bond
*every cellulose molecule has 500 to 15000 glucose molecule
*Length 4 μm
4) hemicellulose-
*It is a polysaccharide composed of a variety of sugars including xylose, arabinose and mannose.
*Hemicellulose molecules are often branched and hydrophilic.
* Often it becomes highly hydrated and forms gels.
*It is abundant in the primary walls and is also found in the secondary walls.
5) extensin
*A type of Glycoprotein
*3 type, depending upon amino acid quantity
a)HRGP(hydroxy proline rich glycoprotein)
b)AGP(glycine rich protein)
c)PRP(proline rich protein)
6) Gum and Mucilage-
*Starch
*Gums are colloidal plant products, which either dissolve or swell in water.
*Gums appear as a result of breakdown of walls, or mechanical injury.
7) lignin-
*Water insoluble
*Polymer of phenyl propane
*Present in secondary cell wall in large number
*Attached with cellular fibre and microfibril to give mechanical support to cell wall.
8) minerals-
*Silicon and calcium carbonate present as minerals
10) cutin and wax
*Polymer of fatty acid
*Make cell wall waterproof
11)enzyme-
*hydrolase, peroxidase, etc
*Generally cell wall made up of 40% cellulose, 20% hemicellulose, 30% pectin, 10% glycoprotein.
The cell wall is mainly composed of carbohydrate rich materials. The major components of cell wall are cellulose, pectins, hemicelluloses, proteins and phenolics.
1)Pectic acid-
*It is the major component of the middle lamella but is also found in the primary walls.
*Pectic acid is the polymer of about 100 galacturonic acid molecules.
* It is hydrophilic in nature.
* It forms salt bridges with calcium and magnesium ions.
*It is the another major component of the middle lamella but is also found in the primary walls.
*It is a polymer of around 200 galacturonic acid molecules.
*Compared to pectic acid it is less hydrated. It is soluble in hot water.
*glucose polymer is the main chemical component of cell wall
*Glucose molicule are attached with polysaccharide by β1,4 glycosidic bond
*every cellulose molecule has 500 to 15000 glucose molecule
*Length 4 μm
4) hemicellulose-
*It is a polysaccharide composed of a variety of sugars including xylose, arabinose and mannose.
*Hemicellulose molecules are often branched and hydrophilic.
* Often it becomes highly hydrated and forms gels.
*It is abundant in the primary walls and is also found in the secondary walls.
5) extensin
*A type of Glycoprotein
*3 type, depending upon amino acid quantity
a)HRGP(hydroxy proline rich glycoprotein)
b)AGP(glycine rich protein)
c)PRP(proline rich protein)
6) Gum and Mucilage-
*Starch
*Gums are colloidal plant products, which either dissolve or swell in water.
*Gums appear as a result of breakdown of walls, or mechanical injury.
7) lignin-
*Water insoluble
*Polymer of phenyl propane
*Present in secondary cell wall in large number
*Attached with cellular fibre and microfibril to give mechanical support to cell wall.
8) minerals-
*Silicon and calcium carbonate present as minerals
10) cutin and wax
*Polymer of fatty acid
*Make cell wall waterproof
11)enzyme-
*hydrolase, peroxidase, etc
*Generally cell wall made up of 40% cellulose, 20% hemicellulose, 30% pectin, 10% glycoprotein.
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