# How does uracil differ from thymine?

May 10, 2015

Thymine and uracil are both pyrimidines consisting of a ring containing four carbon atoms and two nitrogen atoms. The C5 atom of thymine has a methyl group $\text{(-CH"_3)}$ attached to it, while uracil does not. The methylation of thymine makes the DNA more stable and protects it from attack from certain enzymes. Source:
http://mbotc.tumblr.com/post/14843843501/thymine-vs-uracil