A large organic compound is called a macromoleculewhich in many cases is
a polymer. Amacromoleculecan be reduced to its monomer in a process called
hydrolysis, which adds water molecules to the polymer.
There are four types of organic compounds that are macromolecules. These are:- Carbohydrates
- Lipids
- Proteins
- Nucleic acids
Carbohydrates
Carbohydratesstore energy from an organism in the form of sugar, starches and
in the human body, glucogen. Celluloseis also a carbohydrate used as bulk to
move food and waste through the gastrointestinal tract. Carbohydrates are also
used as material in the cell wall. Carbohydrates are organized into three major
Carbohydrate groups. These are:- Monosaccharides. Some of the important monosaccharides are: glucose, the
main energy source for an organism; fructose, acquired by eating fruit; galac-
tose, which is in milk; deoxyribose, DNA; and ribose, RNA. A monomer is
also a monosaccharide. - Disaccharides. This is a combination of two monosaccharides bonded dur-
ing dehydration synthesis. Sucrose (table sugar) and lactose (milk sugar)
(^40) CHAPTER 2 Chemical Elements of Microorganisms
O
H
HH
H
H
O H
OH
OH OH
H
HO
HO
H
OH HO
CH 2 OH
CH 2 OH
HOCH 2
Glucose
C 6 H 12 O 6
Fructose
C 6 H 12 O 6
Fig. 2-9. A carbon cain is used to show the compound fructose.