Ionic Bonds

What are ionic bonds ?

What kinds of biological molecules form ionic bonds?

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)

Here is another representation of the carboxyl group. In this case the covalent bonds are shown by the lines and the shared electrons are shown by the black dots.

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.

What function do ionic bonds have in biology?

They are important in all biological processes. A few examples are: