DNA is negatively charged, due to the phosphate groups in its phosphate-sugar backbone ... may be highly irregular and not quite the uniform structure depicted in instructive drawings such ...

Laying the Groundwork: Levene Investigates the Structure of DNA Meanwhile ... a sugar molecule, and a phosphate group. Levene made his initial proposal in 1919, discrediting other suggestions ...

a phosphate group, and one of four nitrogenous bases: adenine (A), uracil (U), guanine (G), or cytosine (C). RNA is similar to DNA but contains uracil instead of thymine (T) and has a single-stranded ...