uracil u·ra·cil (yur'ə-sĭl)
A pyrimidine base that is an essential constituent of RNA.
|uracil (yr'ə-sĭl) Pronunciation Key
A pyrimidine base that is a component of RNA. It forms a base pair with adenine during transcription. Uracil is therefore structurally analogous to thymine in molecules of DNA. Chemical formula: C4H4N2O2.