1. Building blocks of RNA
The basic components of RNA are the same than for DNA (see the DNA page) with two major differences. The pyrimidyne base uracil replace thymine and ribose replace deoxyribose (see the sugars, purines and pyrimidines pages). Adenine and Uracil for a base pair formed by two hydrogen bonds.
2. Nucleosides and nucleotides
For RNA, nucleosides are formed similarly to DNA with ribose replacing deoxyribose Uracil 5' monophosphate is given as an example.
|Uracil 5' monophosphate|
RNA also contain "unusual" nucleotides (formed after the RNA synthesis is complete). These includes: Ribothymidine (T), dihydrouridine (D), pseudouridine (Y) and inosine (I). A table of the modifies RNA bases can be found here.
3. RNA Structure.
|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)