Cellulose Flashcards
Cellulose is a
polysaccharide
polysaccharide are
are macromolecules that are polymers formed by many monosaccharides joined by glycosidic bonds in a condensation reaction to form chains.
These chains may be:
Branched or unbranched
Folded (making the molecule compact which is ideal for storage, eg. starch and glycogen)
Straight (making the molecules suitable to construct cellular structures, eg. cellulose) or coiled
Polysaccharides are insoluble in water
Cellulose – structure
Is a polymer consisting of long chains of
β-glucose joined together by 1,4 glycosidic bonds
As β-glucose is an isomer of α-glucose to form the 1,4 glycosidic bonds consecutive β-glucose molecules must be rotated 180° to each other
Due to the inversion of the β-glucose molecules many hydrogen bonds which give it …..
the long chains giving cellulose it’s strength
Cellulose – function
Cellulose is the main structural component of cell walls due to its strength which is a result of the many hydrogen bonds found between the parallel chains of microfibrils
The high tensile strength of cellulose allows it to be stretched without breaking which makes it possible for cell walls to withstand turgor pressure
The cellulose fibres and other molecules (eg. lignin) found in the cell wall form a matrix which increases the strength of the cell walls
The strengthened cell walls provides support to the plant
Cellulose function (transport wise
Cellulose fibres are freely permeable which allows water and solutes to leave or reach the cell surface membrane
Cellulose structure (fibre)
As few organisms have the enzyme (cellulase) to hydrolyse cellulose it is a source of fibre