Characteristic Features of Rna

Characteristic features of RNA

Messenger, ribosomal, and transfer RNA are the main kinds of RNA in living cells.

The cytoplasm contains a further class of RNA, called small cytoplasmic RNA (scRNA), which mainly exists in the form of RNA-protein complexes. Within a special region of the nucleus, called the nucleolus, another class of RNA is found. It is called small nucleolar RNA (SnoRNA) and functions in the manufacture of ribosomal RNA.

MESSENGER RNA

The stretch of DNA that codes for one protein is called a gene. In transcription, an mRNA molecule is made from a gene. The bases in the RNA correspond to the bases in the DNA, according to the standard base-pair rules found in DNA.The synthesis of the DNA is catalysed by the enzyme RNA polymerase. What happens next depends on whether the life form concerned is a bacterium or a eukaryote. Most large and familiar forms of life are eukaryotes: human beings, as well as insects, plants, and seaweeds, are eukaryotes. Technically, eukaryotes are creatures whose cells contain a distinct nucleus. Prokaryotic cells, such as bacteria, lack a nucleus.

RIBOSOMAL RNA

Ribosomes have a similar general structure in all life forms, but they vary in size between bacteria and eukaryotes. All ribosomes are made up of two subunits, one small and one large. The two units are made up of ribosomal RNA and proteins.

Ribosomal