RNA BLOG

RNA molecules are also polynucleotides with a sugar-phosphate backbone and four kinds of bases. The main differences between RNA and DNA are:

• RNA molecules are single-stranded
• The sugar in RNA is a ribose sugar (as opposed to deoxy-ribose) and has an –OH at the 2' C position highlighted in red in the figure below (DNA sugars have –H at that position)
• Thymine in DNA is replaced by Uracil in RNA. T has a methyl (-CH₃) group instead of the H atom shown in red in U.

The picture shows an ATP molecule (adenosine tri-phosphate) about to be incorporated into an RNA chain with the release of a di-phosphate).

RNA molecules do not have a regular helical structure like DNA. Instead, they can form complicated 3-dimensional structures where the strands can loop back and form intra-strand base-pairs from self-complementary regions along the chain.