Chemically, what is lignin, and how do plants make it?

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Offline chris

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Woody stems in plants are said to be "lignified". But what is lignin, and how do plants make it?
« Last Edit: 26/07/2015 14:11:54 by chiralSPO »
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Offline chiralSPO

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Re: Chemically, what is lignin, and how do plants make it?
« Reply #1 on: 26/07/2015 14:28:04 »
Lignin is a very complex biopolymer. Unlike cellulose( https://en.wikipedia.org/wiki/Cellulose ), which is made up of many identical subunits (monomers), all connected in the same way to make a long straight chain, lignin is composed of multiple similar monomer units, which can be connected to each other in many different ways, resulting in a branched, cross-linked web. (https://en.wikipedia.org/wiki/Lignin) This "web" is a component of cell walls in woody plants, where it holds the cellulose together more strongly.

The monomer subunits are made by modification of the amino acid phenylalanine. Then the monomers undergo a radical polymerization process that results in a random assortment of linkage types and configurations.