Thymine

Summary

Thymine, abbreviated as the letter T, is a nitrogenous base that serves as a building block for nucleotides found in DNA. Thymine’s structure contains only one six-membered ring, meaning that it belongs to the pyrimidine family of one-ringed, nitrogen-containing bases. Branching out from this one ring are three functional groups: two carbonyls at the 2nd and 4th position and a methyl group at the 5th position. Thymine is usually only found in DNA, and not in RNA.

Key Points

• Thymine (T)
  • Characteristics
    • Nitrogenous Base
      • Organic molecules made up of nitrogen-containing ring structures
      • Each base has a unique structure, with its own set of functional groups attached to the ring structure 
    • Building block of Nucleosides and Nucleotides
      • Thymidine is a nucleoside with thymine as its base
    • Present in only DNA
      • Uracil is its unmethylated counterpart in RNA
  • Structure
    • Chemical Formula = C5H6N2O2
    • 
    • Pyrimidine
      • Contains 1 ring (six-membered)
    • Functional Groups
      • Carbonyl (–C=O)
        • Located at 2nd position
      • Carbonyl (–C=O)
        • Located at 4th position
        • Important in differentiating vs. cytosine
      • Methyl (–CH3)
        • Methyl at 5th position
        • Important in differentiating vs. cytosine and uracil