Describe the structure of a RNA polynucleotide chain having four different types of nucleotides. (3)
RNA is ribose nucleic acid.
1. It has only one polynucleotide chain. Chain has polarity.
2. In RNA 4 nitrogenous bases are present: Adenine, guanine, uracil and cytosine.
3. Backbone of RNA is made of ribose-pentose sugar and a phosphate group.
4. A nitrogenous base is linked to the pentose sugar through a N-glycosidic linkage to form a nucleoside such as adenosine, guanosine, cytidine and uridine.
5. When a phosphate group is linked to of nucleoside through phosphodiester linkage, a corresponding nucleotide is formed.
6. More nucleotides are joined to form a polynucleotide. RNA has a single chain of polynucleotide.
7. A polymer has at one end a free phosphate moiety at of ribose sugar , end of polynucleotide chain, at the other end to the polymer has a free OH group which is referred to as end of the polynucleotide chain.
8. The nitrogenous bases linked to sugar moiety project out from the backbone.