The chemistry of DNA, RNA, and proteins is of course different, although carbon, hydrogen, oxygen, and nitrogen are prominently represented in all three. DNA and RNA add phosphorous to the mix, but don't have the sulfur found in some amino acids.
The table below shows the nucleotides for DNA and RNA. Thymine is found only in DNA, while its chemical cousin uracil is found in RNA.
Foldit colors these nucleotides in yellow and purple when "hydro" or a related coloring option is selected. Foldit also classifies them as small or large. When DNA is in its normal double helix configuration, small yellow is bonded with large yellow and small purple is bonded with large purple across the two helixes. These pairings may also occur in RNA, but RNA is more flexible, and many other pairings are possible.
|base||code||DNA code||RNA code||color||size|