CELLULOSE (CPG pg11 & 168)

Major component of cell walls in plants
Long, unbranched chains of beta-glucose, joined by glycosidic bonds
Glycosidic bonds between the sugars are straight, so the cellulose chains are straight
50 & 80 cellulose chains are linked together by a large number of hydrogen bonds to form strong threads called microfibrils
1. Strong fibres mean cellulose provides structural support for cells (plant cell walls)
2. Glue that holds the microfibrils is composed of short, branched polysaccharides known as hemicellulose & pectins (School book pg.173)
  1. These short polysaccharides bind both to the surface of the cellulose & to each other & hold the cellulose & microfibrils together (School book pg.174)
  2. Pectins act as cement & hold the cells together (School book pg.174)
  3. Arrangement of the cellulose microfibrils within the hemicellulose & pectins make the cell walls strong (School book pg.174)
    1. Microfibrils are laid down at different angles, which makes the wall strong & flexible (School book pg.174)
Hydrogen bonds form between the -OH groups in neighbouring cellulose chains, forming bundles called microfibrils. (School book, pg173)
1. Individually, the hydrogen bonds are relativley weak compared with the glycosidic bonds, but together the large number of hydrogen bonds in the microfibril produces a strong structure (school book)

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	Criado por dolce-n-banana quase 11 anos atrás