Chemical Composition of the Body 35Figure 2.15 The structure of glycogen. Glycogen is a polysaccharide composed of glucose subunits joined together to
form a large, highly branched molecule.
OOOOOOHOHCH 2 OH
OOHOHCH 2 OH
OOHOHCH 2
OOHOHCH 2 OHOOOOOOHOHCH
2 OHOOHOHCH(^2) OH
O
OH
OH
CH
(^2) OH Glycogen
Figure 2.16 Dehydration synthesis of disaccharides. The two disaccharides formed here are ( a ) maltose and ( b ) sucrose
(table sugar). Notice that a molecule of water is produced as the disaccharides are formed.
See Test Your Quantitative Ability section of the Review Activities at the end of this chapter.
Glucose
Glucose Glucose
Fructose
Maltose Water
Water
CH 2 OH
H
(a)
(b)
H
H
H
H
OH
OH
HO OH
O
CH 2 OH
H H
H
H
H
OH
OH
HO
O
O
CH 2 OH
H 2 O
H 2 O
H H
H
H
H
OH
OH
OH
O
CH 2 OH
H H
H
H
H
OH
OH
HO OH
O
- CH 2 OH
CH 2 OH
CH 2 OH
H H
H
H
H
H
H
H
OH
OH OH
OH
OH
OH
HO
O O
CH 2 OH
H CH 2 OH
H
OH H
OH
O
CH 2 OH
H H
H
H
H
OH
OH
HO
O
O
++
- CH 2 OH
- = +
Sucrose