Wanishahid
it is the carbon atom in
the "center" of the
molecule, it is the
carbon atom to which 4
different atoms or
groups of atoms are
attatched.
in amino acids, for
example, there is a
central carbon atom, to
which are attatched a
hydrogen atom, an
amine group, a
carboxylic acid group
and a side-chain that
varies between
different amino acids.