Describe How the Uses of Plant Fibres and Starch May Contribute to Sustainability

Describe how the uses of plant fibres and starch may contribute to sustainability
The cell walls of all vascular plants contain a material called lignin.   Lignin is water-resistant and it reinforces cell walls, keeping them from collapsing. This is especially important in the xylem, because the column of water in the hollow xylem cells is under strain and without the lignin reinforcement the cells would collapse. Lignin provides the support for stems and leaves and supplies the strength and rigidity of plant walls; secondly, lignin provides resistance to diseases, insects, and cold temperatures. The plant cell wall surrounds the cell membrane; the cell wall is made up of multiple layers of cellulose which are arranged into primary and secondary walls. Cellulose is the most common organic compound on Earth. About 33% of all plant matter is cellulose - the cellulose content of cotton is 90% and wood is 50% cellulose. Cellulose is a polymer made of repeating glucose molecules and is an example of a polysaccharide. Cellulose is similar in form to complex carbohydrates like starch and glycogen. It differs from starch, which is a coiled molecule because of the differences in structure that mean that, compared to starch and other carbohydrates, cellulose can not be broken down into its glucose subunits by any enzymes produced by animals. Sclerenchyma is composed of dead cells with extremely thick secondary walls cell walls composed of cellulose and lignin; there are two types of sclerenchyma cells, fibres and sclereids. Fibres are generally long, slender cells, which commonly occur in strands or bundles.
Before we can use the plant fibres they first have to be extracted from the plant itself. The process of extraction often used is called retting. Retting involves using water or micro-organisms to dissolve or rot away the cellular tissues surrounding the fibre bundles. After this the fibres can then be obtained, usually sclerenchyma cells or xylem tissue because of...