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 [...]
In this article we will discuss about the translation of amino acid to tRNA in cytoplasm. (i) Activation of Amino acids: Amino acids must be necessarily activated before their involvement in peptide synthesis (Fig. 4-10). The process is accomplished by the binding of an amino acid to ATP enzymatically and its consequent transference to tRNA. (ii) Transfer of amino acid [...]
In this article we will discuss about the maturation of mRNA from HnRNA. In higher organisms, within the nucleus, heterogenous nuclear RNA (HnRNA) or high molecular weight RNA (HMW RNA) or DNA-like-RNA (dRNA) is synthesized. These molecules are larger than mRNA and used in cytoplasm. Polymerase-I is added at 3'-end of HnRNA. Subsequently mRNA molecule is released when HnRNA having [...]