Thymine is one of the pyrimidine bases present in nucleic acids.
Structure of cytosine
Cytosine is a nitrogen base belonging to the pyrimidine family, which has the chemical formula C5H6N2O2. It is therefore a heterocyclic molecule, as the rings are not only composed of carbon.
Function of thymine
Thymine is involved in the formation of thymidine (in which thymine is bound to a ribose) which is contained in particular in DNA, TMP, TDP and TTP. Thymine is replaced in RNA by another protein base, uracil.
In DNA, thymine is bound to adenine by two hydrogen bonds.
Thymine is a pyrimidine base. © Vesprcom, Wikimedia, public domain