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 [...]
The following points highlight the top four models proposed for chromosome structure. The models are: 1. Molecular Model 2. Multi-Stranded Model or Polyneme Chromosome Model 3. General Chromosome Model 4. Folded Fibre Model. Chromosome Structure: Model # 1. Molecular Model: This model of chromosome structure was proposed by Taylor and coworkers in 1957, 1963 and is based on the semiconservative [...]