From Wikipedia,
the free encyclopedia.
Carbon forms the backbone of
biology for all life on Earth.
Complex molecules are made up of
carbon bonded with other elements,
especially
oxygen,
hydrogen and
nitrogen. It is these elements
that living organisms need, among
others, and carbon is able to bond
with all of these because of its
four
valence electrons. Since no
life has been observed that is not
carbon-based, it is sometimes
assumed in
astrobiology that life
elsewhere in the universe will
also be carbon-based. This
assumption is referred to by
critics as
carbon chauvinism, as it
may be possible for life to form
that is
not based on carbon.
