The sucrose molecule has many oxygen-hydrogen (O–H) bonds which are polar. The charge-density model shows the positive areas near the hydrogen atom as blue and the negative area near the oxygen atom ...

Several scientists put forth suggestions for how this might occur, but it was Levene's "polynucleotide" model that proved ... nitrogen-containing bases, a sugar molecule, and a phosphate group.

(It takes two bases to form a rung -- one for each side of the ladder.) A sugar molecule, a base, and a phosphate molecule group together to make up a nucleotide. Nucleotides are abundant in the ...

In the late nineteenth century, a German biochemist found the nucleic acids, long-chain polymers of nucleotides, were made up of sugar ... accepted as the genetic molecule. Scientists still ...