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 [...]
In this article we will discuss about the organisation of immunoglobulin genes with special reference to multi-gene organisation. It has become clear that the B-lymphocytes of the immune system produce antibodies in the presence of antigen. The antibodies are formed from the assembly of some protein chains. In mammals, enormous amount of antibodies are produced. For this, there must be [...]