structure & function of cellulose Flashcards
1
Q
what is the function of cellulose?
A
- cellulose provides structural support for the plant
2
Q
where can cellulose be found?
A
- in all plant cell walls
3
Q
can cellulose be hydrolysed to glucose?
A
- cellulose can only be hydrolysed by the enzyme cellulase, which is only present in herbivores
4
Q
what is the structure of cellulose?
A
- it is an unbranched chain
5
Q
what does cellulose consist of?
A
- many beta-glucose residues linked by beta (1-4) glycosidic bonds
6
Q
what is 1 unique feature about cellulose that starch & glycogen do not have?
A
- the alternate beta-glucose molecules must be rotated 180° to each other
7
Q
why must the alternate beta-glucose molecules must be rotated 180° to each other in cellulose?
A
- to allow the hydroxyl groups to be in close proximity for condensation reaction to take place,
- leading to the formation of a straight beta-glucose chain in cellulose
8
Q
what does the straight chain of cellulose allow for?
A
- the straight cellulose chain allows hydroxyl groups to project outwards from each chain in all directions,
- leading to the formation of hydrogen bond cross-linking between neighbouring cellulose chains
9
Q
what does hydrogen bond cross-linking between cellulose chains allow for?
A
- it allows the cellulose chains to associate into large bundles called microfibrils
10
Q
are cellulose fibres formed outside or inside the cell?
A
- OUTSIDE THE CELL
11
Q
what does the cell surface membrane of a plant cell contain?
A
- cellulose synthase enzymes!
