2.6 CHAPTER 2. ORGANICMACROMOLECULES
cellulose are two example of carbohydrates that are polymers composed of glucose
monomers.(a)
(b)
C 4
H
OH
C 5
CH 2 OH
H
O
C
H
C 2 OH
H
OH
C 3
OH
H
+ C 4
H
OH
C 5
CH 2 OH
H
O
C
H
C 2 OH
H
OH
C 3
OH
H
C 4
H
OH
C 5
CH 2 OH
H
O
C
C (^2) H
H
OH
C 3
H
C 4
C 5
CH 2 OH
H
O
C
H
C 2 OH
H
OH
C 3
OH
H
H
O + H 2 O
Figure 2.11: Two glucose monomers (a) undergo a condensation reaction to produce
a section of a carbohydrate polymer (b). One molecule of water is produced for every
two monomers that react.- Starch
Starch is used by plantsto store excess glucose,and consists of long chains of
glucose monomers. Potatoes are made up almost entirely of starch. This is why
potatoes are such a goodsource of energy. Animals are also able to store glucose,
but in this case it is stored as a compound called glycogen, rather than as starch.- Cellulose
Cellulose is also madeup of chains of glucosemolecules, but the bonding be-
tween the polymers is slightly different from that in starch. Cellulose isfound in
the cell walls of plants and is used by plants as abuilding material.