let’s start simple. Consider a molecule that is a bit more complex than
water, but not too much so—a small organic molecule composed of
two carbon atoms, one oxygen atom, and six hydrogen atoms joined
together by chemical bonds. This is the molecule ethyl alcohol, or
ethanol, the primary psychoactive component of alcoholic beverages
such as beer, wine, and distilled liquor. In this drawing of the chemical
structure of ethanol, carbon is represented by C, oxygen by O, and
hydrogen by H. Covalent chemical bonds, the sharing of electrons be-
tween atoms, are represented by lines connecting the atoms. One sees
that each carbon has four chemical bonds, reflecting four electrons
to share; each hydrogen has one chemical bond, and the oxygen has
two chemical bonds. The particular molecular shape produced by this
geometric arrangement of atoms confers upon ethanol its peculiar
properties.
et
H “¢ n -O-H
HH
Ethyl alcoholHere are some other relatively simple organic molecules—relatively
simple in that they are built from linear chains of carbon and hydro-
gen, and nothing else. Organic molecules composed solely of carbon
and hydrogen are called hydrocarbons.