The imidazole ring system is often found in biological systems, e.g. in proteins. It is involved in many proton transfer processes as a result of its ability to behave as a base and also as an acid. Show how a knowledge of the chemistry of pyridine and pyrrole can be used to predict the chemistry of imidazole. You should discuss: (i) Basicity (the pKa of the conjugate acid of imidazole is 6.9, of pyridine is 5.2 and of pyrrole is 3.8 ). (ii) Acidity (the pKa of imidazole is 14 and of pyrrole is 17). (ii) Electrophilic aromatic substitution