The mRNAs found in prokaryotes differ from that of eukaryotes in the following ways: (i) The prokaryotic mRNAs are broken down by the ribonuclease into ribonucleotide, hence these are very short lived e.g. 2 minutes in E.coli. The short lived nature is due to changes in environmental conditions. In contrast the eukaryotic mRNAs have longer life i.e. they are metabolically [...]
There are many types of RNAs, but three types of it are described here: 1. Ribosomal RNA (rRNA) 2. Messenger RNA (mRNA) 3. Transfer RNA (tRNA). Type # 1. The Ribosomal RNA (rRNA): The non-genetic RNAs are synthesized on the DNA template and are present in the nucleolus and cytoplasm. Therefore, the base sequences of rRNA and part of DNA [...]
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 [...]