Question

Difference between mRNA and tRNA. Write short notes on the following :

(i) Small nuclear RNA
(ii) Genetic RNA
(iii) Enzymatic RNA

Answer 1

	mRNA	tRNA
1.	It is linear.	It is clover-leaf shaped.
2.	It carries coded, informations.	It carries information for association with an amino acid and an anticode for its incorporation in a polypeptide.
3.	mRNA undergoes additional processing, i.e., capping tailing and splicing.	It does not require any processing.
4.	Nitrogen bases are unmodified.	Nitrogen bases may be modified.

1. Small Nuclear RNAs (snRNAs) : These are found in the nucleus of eukaryotic cells. snRNA has 100 to 215 nucleotides. These are important for DNA replication and processing of long, newly transcribed hnRNA molecules.

2. Genetic RNA (gRNA) : In some viruses, in which, RNA is the hereditary material, gRNA is found. It may be single stranded or double stranded.

3. Enzymatic RNAs : Certain RNAs act as biological catalysts. These are called ribozymes. These are associated with the maturation of hnRNAs. 23S and 28S ribosomal RNAs of ribosomes catalyse formation of peptide bonds during synthesis of polypeptide chains.