The tautomeric forms of each base exist in equilibrium but the amino and lactam tautomers are more stable and therefore predominate under the conditions found inside most cells.

What is tautomeric form of adenine?

Specifically, adenine has the ability to adopt amino and imino tautomeric forms involving the exocyclic group at the 6-position; uracil and thymine have carbonyl functional groups that can participate in keto–enol tautomerism.

What type of compounds show tautomerism?

Tautomerism is an isomerism in which the isomers are readily interchangeable and are in dynamic equilibrium with each other. It is shown by the compounds which have an acidic α−hydrogen. Keto compounds show tautomerism. Recall the keto-enol tautomerism.