Practise IB Biology HL B1.1.6 by analysing beta-glucose 1-4 linkages, alternating chains and hydrogen-bonded microfibrils that strengthen plant cell walls.
Plants have cell walls composed of cellulose.
Describe the structure of cellulose molecules.
a. beta/ β glucose (subunits/monomers in cellulose) / diagram showing position of OH groups in beta glucose molecule;
b. C 1 to C 4 bonds / glycosidic bonds (between glucose molecules);
c. unbranched/linear (polymer/molecule/chain);
d. straight/not helical (polymer/molecule/chain);
e. glucose subunits orientated alternately upwards and downwards/OWTTE;
f. hydrogen bonding between adjacent cellulose molecules/polymers;
Marks can be awarded for annotated
diagrams that make any of mpb to
mpe clear.
3
Marking guidance:
max