Chemistry Reference
In-Depth Information
α
-1,6 linkage
α
-1,4 linkage
CH
2
OH
CH
2
OH
CH
2
CH
2
OH
O
O
O
O
OH
OH
OH
OH
O
O
O
O
OH
OH
OH
OH
(a)
α
-1,4 linked
D
-glucose
α
-1,6 linked
D
-glucose
(b)
Fig. 6.2
Schematic representations of amylopectin, showing the 1,4 and 1,6 glucosidic linkages (a) and
what that means for the whole structure (b).
Table 6.1
Different characteristics of amylose and amylopectin.
Characteristic
Amylose
Amylopectin
Shape
Essentially linear
Branched
Linkage
α
-1,4 (
±
1/1000
α
-1,6)
α
-1,4 and
α
-1,6 (
±
1/25)
Typically 10
5
-10
6
10
7
-10
9
Molecular weight
Films
Strong
Weak
Gel formation
Firm
Non-gelling/soft
Colour with iodine
Blue
Reddish brown
