make a supporting skeleton for its cells.
Simple sugars and starch are energy stores,
while pectins, cellulose, and other cell-wall
carbohydrates are the plant’s structural
materials.
SUGARS
Sugars are the simplest carbohydrates. There
are many different kinds of sugar molecules,
each distinguished by the number of carbon
atoms it contains, and then by the particular
arrangement it assumes. Five-carbon sugars
are especially important to all life because
two of them, ribose and deoxyribose, form the
backbones of ribonucleic acid (RNA) and
deoxyribonucleic acid (DNA), the carriers of
the genetic code. And the 6-carbon sugar
glucose is the molecule from which most
living things obtain the energy to run the
biochemical machinery of their cells. Sugars
are such an important nutrient that we have a