adenine.gif (1306 bytes) For RNA, nucleosides are formed similarly to DNA. RNA exist as a single strand. Hairpin is a common secondary/tertiay structure. It requires complementarity betweem part of the strand. the figure on the left is a schematic representation of the haipin structure.
The chime image below represent yeast tRNA and has been extracted from the RNA structure tour pages from Carnegy Mellon University). colors are set from red at the 3' end to blue at the 5' end.
Double standed RNA can also exists and is generally similar to A-DNA (present is few viruses)