Messenger RNA and translation

The Messenger RNA is a molecule of RNA which encodes a chemical blueprint for a protein product. The Messenger RNA is transcribed from a DNA template and carries coding information to the sites of protein synthesis the ribosomes. Within the ribosomes the mRNA is translated into a polymer of amino acids that is: a protein. As in DNA mRNA genetic information is encoded in the sequence of nucleotides that are arranged into codons consisting of three bases each. Every codon encodes for a specific amino acid except the stop codons that terminate protein synthesis. This procedure of translation of codons into amino acids needs two other kind of RNA: Transfer RNA tRNA which mediates recognition of the codon and gives the corresponding amino acid and ribosomal RNA rRNA which is the central component of the ribosome's protein-manufacturing machinery.

Because prokaryotic mRNA does not required to be processed or transported translation through the ribosome can start immediately after the end of transcription. Thus, it can be said which prokaryotic translation is coupled to transcription and occurs cotranscriptionally. Translation may occur at ribosomes free-floating in the cytoplasm or directed to the endoplasmic reticulum by the signal recognition particle. Thus unlike in prokaryotes eukaryotic translation is not directly coupled to transcription.