ionic bonds are forces of attraction between ions of opposite charge (+and -)
any kind of biological molecule that can form ions
An example of a functional group that can enter into ionic bonds is shown below. The carboxyl group is shown.
Under the right conditions of pH the carboxyl group will
ionize and form the negatively charged COO ion and a positively charged
H ion (or proton)
When ionization of the carboxyl group occurs a proton
dissociates from the OH group, leaving the shared electrons behind with
the oxygen. Thus the COO ion has an excess of electrons over protons and
is an anion. The proton that is released has no associated electron and
is therefore a cation.
They are important in all biological processes. A few examples are:
They play an important role in determining the shapes (tertiary and quartenary structures) of proteins
They are involved in the process of enzymic catalysis
they are important in determining the shapes of chromosomes.
They play a role in muscle contraction and cell shape
They are important in establishing polarized membranes for neuron function and muscle contraction