TYPES OF RNA

MESSENGER RNA (mRNA)

mRNA makes up about 5% of the total RNA composition of the cell. mRNA serves as a template for protein synthesis in a process called translation. In eukaryotes a distinct mRNA molecule is produced for each gene, in contrast, prokaryotic cells have mRNA mol that code for several genes.

 

TRANSFER RNA (tRNA)

Makes up about 15% of the total cellular RNA. tRNA has a distinct stem-loop  ( folds Into a T-shape ) structure and functons in carrying activated amino acids to the ribosome-mRNA during protein synthesis. Each amino acid has at least one tRNA made specifically to carry it to the ribosome.

 

RIBOSOMAL RNA (rRNA)

rRNA makes up about 80% of the total cellular RNA. rRNA is a major constituent of ribosomes- the cellular machinery that are responsible for synthesizing proteins. rRNA gives the ribosome its structure and also plays a catalytic role. In prokaryotes , 3 types of rRNA makes up the ribosomes; 23S, 16S and 5S rRNA. They combine with special proteins to form rbosomes which the reads mRNA to form proteins.

In addition to these, there are other RNA molecules in the cell that have their own specific purposes.

 

SMALL NUCLEAR RNA (snRNA)

They are involved in transforming the pre-mRNA into a mature  and fully functional RNA. They do this by splicing together the exons to form mature mRNA.

 

MICRO RNA (miRNA)

Tiny RNA molecule (1-20 nucleotides in length). Bind to complementary mRNA molecule and inhibit their translation .

 

SMALL RNA

Helps form the signal recognition particle that directs synthesized protein to their intracellular and extracellular destinations.

 

SMALL INTERFERING RNA (siRNA)

Binds to mRNA molecule and stimulates their breakdown.

 

TELOMERASE RNA COMPONENT

Found in eukaryotic enzyme called telomerase. It functions in maintaining the telomeric ends of DNA during replication.