The basic structure of a nucleotide
An RNA nucleotide (top) compared with a DNA nucleotide (bottom)
The molecular structures of purines and pyrimidines are slightly different
Nucleotide Structure Table
Although DNA and RNA nucleotides are very similar, make sure you know the key differences between them: unlike DNA, RNA nucleotides never contain the nitrogenous base thymine (in place of this they contain the nitrogenous base uracil) and unlike DNA, RNA nucleotides contain the pentose sugar ribose (instead of deoxyribose).You don’t need to know the structural formulae of the bases, just which are purines and which are pyrimidines.
A section of a single polynucleotide strand showing a phosphodiester bond (and the positioning of the two ester bonds and the phosphate group that make up the phosphodiester bond)
In condensation reactions, a molecule of water is released. In hydrolysis reactions, a molecule of water is added.