The synthesis of proteins is directed by DNA or genetic RNA, where DNA is absent. The basic information for the polypeptide structure is stored in the polynucleotide chain. The base sequence in the codon determines the amino acids sequence in a particular polynucleotide. In general, there are three views regarding the flow of genetic information and these are one-way, circular [...]
The following points highlight the three main steps involved in mechanism of protein synthesis. The steps are: 1. Initiation of Protein Synthesis 2. Elongation of Polypeptide 3. Termination of Protein Synthesis. Mechanism of Protein Synthesis: Step # 1. Initiation of Protein Synthesis: (i) Amino Acid Activation: The amino acid (AA) is activated by the enzyme "aminoacylsynthetase", and energy is provided [...]
In this article we will discuss about Heterogeneous Nuclear RNA (hnRNA). Unlike prokaryotic mRNA, eukaryotic mRNAs are monocistronic. The primary transcript in eukaryotes is much larger than the mature mRNA and is called Heterogeneous nuclear RNA (hnRNA). It contains unique sequences and has about 10 times as many sequences as the mature mRNA. hnRNA undergoes processing and finally the mRNA [...]