The processed RNA molecules take part in protein synthesis with the help of ribosomes. All the three types of RNAs are involved in protein synthesis in the following main steps: (i) Activation of amino acids, (ii) Transfer of amino acid to tRNA, (iii) Initiation of protein synthesis, (iv) Elongation of the polypeptide chain. During the process of translation the genetic [...]
The tRNA, mRNA and rRNA are involved in the process of transcription. However, an enzyme transcriptase i.e. DNA-dependent RNA polymerase is required for the synthesis of RNA by using ribonucleotide triphosphates i.e ATP, GTP, CTP and UTP. Structure and function of RNA polymerase are described herewith. 1. RNA Polymerase: On a DNA template elongation of RNA chain at each step [...]
In this article we will discuss about the processing of rRNA in prokaryotes (e.g. E. coli) and eukaryotes (e.g. mammals). In prokaryotes (e.g. E. coli) there are seven operons for rRNA. These are dispersed throughout the genome. Each operon consists of one copy of each of the 5S, 16S and 23S rRNA sequences. Coding sequences for tRNA molecules are present [...]