RNA and DNA are both nucleic acids. But whilst DNA basks in the spotlight and gets all the attention, RNA is less well known. Yet the function of RNA is just as important for the manufacture of proteins.
Though similar to DNA, in that it is a nucleic acid, there are some stark differences. Whilst DNA consists of two long twisted strands, sometimes called the double helix, RNA exists as one strand. It is a linear polymer. Both DNA and RNA have four nitrogenous bases; Adenine, Cytosine, Guanine, but instead of Thymine, RNA has a different base, called Uracil.
Before we go any further, what does RNA actually stand for?
Ribo – This is short for ribose and it is a pentose sugar. Contrast this with the sugar group in DNA which is dexoyribose.
Nucleic – Refers to the fact that it originates in the nucleus.
Acid – It is an acidic compound.
So what is the function of RNA? It is an intermediary between DNA, which houses the instructions to make a protein, and the ribosomes, which are a cell’s protein making factory. It carries out its role by transcribing the genetic instructions inside the nucleus by producing a complementary strand of RNA. It is a copy of a segment of DNA. This is translated in the ribosomes to produce a protein. It is a very complex process and there are several different types of RNA involved.
Messenger RNA shuttles the information out of the nucleus.
Transfer RNA is involved in decoding this information.
Ribosomal RNA is involved in building the protein in a ribosome.
Where is RNA?
RNA is found in several locations in the cell. It sits inside the nucleus as messenger RNA (mRNA) and in the cell cytoplasm as transfer RNA (tRNA). It can also be found in the ribosomes as ribosomal RNA (rRNA).