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Lignin

Lignin

(Science: plant biology) organic substance which act as a binder for the cellulose fibres in wood and certain plants and adds strength and stiffness to the cell walls.

The chemical structure of lignin is composed of a complex polymer of phenylpropanoid subunits, laid down in the walls of plant cells such as xylem vessels and sclerenchyma. It imparts considerable strength to the wall and also protects it against degradation by microorganisms. It is also laid down as a defence reaction against pathogenic attack, as part of the hypersensitive response of plants. A complex polymer; the chief non-carbohydrate constituent of wood; binds to cellulose fibers to harden and strengthen cell walls of plants.A compound found in cell walls, and this non living component provides a structural function in xylem and bark in plants.


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Re: Why is lignin deposited.........

Thanx a lot friend... The third link was very useful

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by sinjanj
Sun Apr 27, 2008 6:02 am
 
Forum: Cell Biology
Topic: Why is lignin deposited.........
Replies: 3
Views: 977

Why is lignin deposited.........

http://en.wikipedia.org/wiki/Xylem http://en.wikipedia.org/wiki/Lignin http://en.wikipedia.org/wiki/Cellulose

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by MichaelXY
Sat Apr 26, 2008 7:30 pm
 
Forum: Cell Biology
Topic: Why is lignin deposited.........
Replies: 3
Views: 977

Why is lignin deposited.........

Plz answer my doubts.. Here in this thead I'll post my doubts regarding cell wall.. plz revisit for updates 1>Why is lignin deposited in all the cellulose layers of the xylem vessel?? one more thing is that, what exactly do we mean by "cellulose layers" of xylem vessels?

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by sinjanj
Thu Apr 24, 2008 3:51 pm
 
Forum: Cell Biology
Topic: Why is lignin deposited.........
Replies: 3
Views: 977

Why don't mammals produce cellulase?

... that arrise randomly. And we can only speculate that in our case, it didn't arrise. By the way, the main constituent of wood is not cellulose, but lignin. Lignin is a branched polymer made out of some phenolic monomers, derived from the aminoacid phenylalanine.

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by MrMistery
Mon Jul 09, 2007 6:10 pm
 
Forum: General Discussion
Topic: Why don't mammals produce cellulase?
Replies: 12
Views: 1842

How do Plants support themselves?

I understand that lignin in dead tracheid cells form xylem vessels and helps give structure and support. But is their any other major factor that helps a plant stay upright? After all, in some trees hundreds of tonnes must need supporting ...

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by elwes
Sun Jan 21, 2007 4:32 pm
 
Forum: Botany Discussion
Topic: How do Plants support themselves?
Replies: 4
Views: 1938
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