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Solving Problems: A Chemistry Handbook
Chemistry: Matter and Change
239
SOLVING PROBLEMS:
A CHEMISTRY HANDBOOK
CHAPTER 23
Polysaccharides A polymer of many monosaccharides bonded
into a chain is called a polysaccharide. Starch is a polysaccharide
that consists only of glucose units. Starch is made by plants as a
means of storing glucose for future use as food. Plants also link
glucose units together in a different way to form the polysaccharide
cellulose, which forms plant cell walls. Animals store glucose as a
polysaccharide called glycogen, which is similar to starch.
Practice Problems
Select the letter of the choice that best completes the statement
or answers the question.
9. Starch is a
a. simple sugar.
c. cellulose.
b. monosaccharide.
d. polymer.
10. Simple sugars do not ordinarily contain a(n) _____ group.
a. hydroxyl
c. carbonyl
b. amide
d. aldehyde
11. Glucose is a(n)
a. polysaccharide.
c. part of cellulose.
b. amino acid.
d. 5-carbon sugar.
12. Which of the following might be called “animal starch”?
a. glucose
c. glycogen
b. plant starch
d. cellulose
23.3 Lipids
Lipids are the nonpolar substances—fats, waxes, and oils—produced by living things. Lipids are not polymers, and their chemical
structures vary widely.
Fatty Acids The most familiar lipids are the plant oils and animal
fats. These lipids are esters of fatty acids, which are carboxylic
acids with long, straight hydrocarbon chains usually having between
12 and 24 carbon atoms. The simplest fatty acids are the saturated
fatty acids, which have no double bonds between carbon atoms.
Many other fatty acids have one or more double bonds between carbon atoms and, as a result, are unsaturated fatty acids.
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