Topic summary
Nucleoside diphosphate
Extracted from the Wikipedia article Nucleotide.
Structure
A nucleotide is composed of three distinctive chemical sub-units: a five-carbon sugar molecule, a nucleobase (the two of which together are called a nucleoside), and one phosphate group. With all three joined, a nucleotide is also termed a "nucleoside monophosphate", "nucleoside diphosphate" or "nucleoside triphosphate", depending on how many phosphates make up the phosphate group.