
The cell and its basic mechanisms 25
such as an enzyme. There a re many different types of proteins. P roteins are
used to suppo rt the cell structure, to break down chemicals, to build new chem-
icals, to transport items, and to regulate production. Every human being has
about 22,000 putative genes
4
that produce proteins. Many of these genes a re
totally identical from perso n to person, but o thers show varia tion in different
people. The genes de termine hair color, eye color, sex, per sonality, and many
other traits that in combination make everyone a unique entity. Some genes
are involved in our growth and development. These g e ne s act as tiny