Functions of RNA
(a) RNA, like DNA has shown to be a general constituent of prokaryotic and eukaryotic cells.
(b) RNA molecules are not as stable as DNA, they also serve as genetic information carrier in some organisms e.g some viruses where RNA is their genetic material.
(c) The main functions of tRNA include: Transportation of specific amino acids to the ribosome’s decoding the genetic information in the messenger RNA in terms of the proper amino acid to be inserted in the sequence of protein/polypeptide synthesised.
(d) tRNA carries one amino acid and also possess an anticodon by which it recognizes the message on the mRNA template during protein synthesis.
(e) Transfer RNAs have two primary active sites, the 3’hydroxyl terminus to which specific aminoacid are attached covalently and the anticodon triplet.
(f) Ribosomal RNAs (rRNA) serve as a structural framework for the ribosomes. The hinging mechanism between the two ribosomal subunits enables translocation and mRNA movement.
(g) Messenger RNA (mRNA) are direct carriers of genetic information from the nucleus to the cytoplasmic ribosomes.
(h) Eukaryotic mRNA contains information for only one polypeptide and is therefore monocistronic whereas prokaryotic mRNA can contain information for more than one polypeptide chain and therefore designated polycistronic.
Intext Questions
1. Nucleic acid itself exist as two different forms namely …………….. and
……………..
2. DNA acts as a ……………..
3. …………….. are not as stable as DNA
4. …………….. are direct carriers of genetic information from the nucleus to the cytoplasmic ribosomes
(a) mRNA (b) rRNA (c) tRNA (d) DNA
5. Prokaryotic mRNA can contain information for more than one polypeptide chain and therefore designated ……………..
