In this article we will discuss about the replication of eukaryotic chromosome. Taylor in 1958 used radioactive thymidine (3H-thymidine) to label Viciafaba root tip chromosomes. He showed that the chromosomes replicated in a semiconservative manner, and proposed that each chromatid was made up of a single DNA molecule. Thus each sister chromatid is composed of one of the two progeny [...]
In this article we will discuss:- 1. Meaning of tRNA 2. Structure of tRNA 3. Initiator Transfer RNA. Meaning of tRNA: Transfer RNAs (tRNAs), also called "soluble RNAs" (sRNAs) are small molecules varying from 75 to 100 nucleotides in length. They carry amino acids and bring them to ribosomes to form the polypeptide chain. There are 20 amino acids but [...]
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 [...]