Structure of a nucleoside triphosphate
(= nucleotide)

The base is attached to the 1'-C of the sugar, and the inorganic phosphates to the 5'-C. The pentose (5-carbon) sugar is identifiable as a deoxyribose by the absence of an -O- from the hydroxyl group on the 2'-C as compared with the 3'-C.

Figure © 2012 TA Brown, Introduction to Genetics (1st ed.); additional text © 2014 by Steven M. Carr