Zusammenfassung der Ressource
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
- Strong fibres mean cellulose
provides structural support for cells
(plant cell walls)
- Glue that holds the microfibrils is
composed of short, branched
polysaccharides known as hemicellulose
& pectins (School book pg.173)
- These short polysaccharides
bind both to the surface of the
cellulose & to each other & hold
the cellulose & microfibrils
together (School book pg.174)
- Pectins act as cement & hold the
cells together (School book
pg.174)
- Arrangement of the cellulose microfibrils within the
hemicellulose & pectins make the cell walls strong (School book pg.174)
- 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)
- 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)