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 [...]
In this article we will discuss about the composition and structure of proteins. Composition of Proteins: Proteins are large molecules consisting of many amino-acids connected by "peptide linkages". Peptide bond is produced when carboxyl radical of one amino acid reacts with the amino (-NH2) group of the other amino acid. The basic structural formula of amino acids is shown in [...]
In this article we will discuss about the changes in chromatin structure during transcription. Displacement of nucleosomes: During transcription, some changes in the chromatin structure occur in the region of transcription. RNA polymerase is comparatively larger in size than the nucleosomes. The molecular weight of RNA polymerase is about 5,00,000 Daltons, while that of nucleosome is about 2,60,000 Daltons. Lewin [...]