Meaning of messenger RNA (mRNA)
What is messenger RNA (mRNA):
Messenger RNA (mRNA) is a type of ribonucleic acid. Nucleic acids, such as ribonucleic acid or RNA, store and transport the genetic information that will define the characteristics of each cell.
In this sense, the messenger RNA is responsible for transporting the genetic information collected from the DNA (deoxyribonucleic acid) to the ribosomes that translate this information to synthesize the necessary proteins.
The mRNA fulfills a different function in prokaryotic (without a defined nucleus) and eukaryotic (with a defined nucleus) cells.
In prokaryotic cells, such as bacteria, transcripts from mature RNA are immediately translated into proteins.
In contrast, in eukaryotic cells, as in humans, for example, mature RNA collects and transports genetic information from DNA through the nucleus to ribosomes.
Structure of messenger RNA
Structure of mRNA formation in eukaryotic cells
The structure of mRNA is more complex in eukaryotic cells than in prokaryotes. In the cells of eukaryotic or defined nucleus cell organisms, the mRNA must undergo the RNA splicing process.
RNA splicing is the removal of introns and the attachment of exons from the previous mRNA, also called as pre-mRNA. Introns are apparently useless code segments and are therefore removed. Instead, the exons are the ones left in the mature mRNA.
Furthermore, the mRNA of eukaryotic cells differ from prokaryotic cells by having a Cap 5 "group on one end and a 3" tail on the other that will help ribosomes to effectively translate the information.
Cap 5 "is a modified guanine (G) nucleotide that protects mRNA from degradation and helps binding to the ribosome to be read.
The 3 "tail contains hundreds of adenine nucleotides (A) that give the mRNA greater stability to travel from the nucleus to the cytosol.