Full Form of RNA – Structure of RNA – Synthesis of RNA

Full Form of RNA:

Ribonucleic Acid

RNA Full Form is Ribonucleic Acid. RNA refers to a polymeric molecule that is essential in various biological aspects such as decoding, coding, regulation of genes. RNA is extremely essential for life forms, as it along with Deoxyribonucleic Acid (abbreviated as DNA) and carbohydrates and proteins together, forms three crucial macromolecules in all life forms. The structural characteristics of RNA are very much similar to that of DNA; RNA is basically a long chain of nucleotides however there is one major difference between the two, which is that RNA is generally found in the form of single strand folded but this is not the case with DNA.

Every cellular organism makes use of messenger RNA (abbreviated as mRNA) for the purpose of conveying genetic information ( through nitrogenous bases such as adenine, uracil, cytosine, and guanine) that causes synthesis of particular proteins. Interestingly, several viruses use RNA genome for the purpose of encoding genetic information. Many RNA molecules are responsible for conducting catalytic biological reactions, communicating various responses received to cellular signals, or for monitoring gene expression.

Protein synthesis, of all the processes, is peculiarly important to mRNA molecules, which causes proteins to assemble upon ribosomes. This entire process makes use of transfer RNA (abbreviated as tRNA) for delivering amino acids to the ribosome, which eventually results in ribosomal RNA (abbreviated as rRNA) linking amino acids together for the purpose of forming proteins.

Full Form of RNA - Structure of RNA - Synthesis of RNA
Full Form of RNA – Structure of RNA – Synthesis of RNA

The aforementioned paragraphs give light on some of the essential aspects of RNA but all of it needs further elaboration because RNA is extremely important for life forms. Thus, the following paragraphs will highlight some essential aspects of RNA with greater detail. So, here are five things or facts about RNA that every person must definitely know about:

Structure of RNA

Every nucleotide of RNA comprises of the ribose sugar, having carbons numbered from 1’ to 5’. On the 1’ position, there is a base group attached, which are basically adenine (indicated as A), cytosine (indicated as C), guanine (indicated as G), or Uracil (indicated as U). Guanine and Adenine are actually purines whereas uracil and cytosine are called pyrimidines. On the 3’ position, there is a phosphate is attached .

An essential structural characteristic of RNA is the presence of hydroxyl group, which is placed at 2’ position of the ribose sugar. This group is key to the structural feature of RNA as it causes the formation of A-form geometry. This A-form geometry results in major grooves as well as a very wide minor groove.

A great number of modifications can be found in tRNA, with nucleosides and pseudouridine attached with 2’-O-methyl ribose in rRNA are commonly found. Functions of each of such modifications have not been fully experimented upon.

Synthesis of RNA

RNA polymerase is an enzyme that is responsible for the synthesis of RNA. It performs such functions with the help of DNA, which is used as a template, and this process of synthesis is called transcription. The process of transcription initiated by binding the enzyme to a sequence of the promoter in the DNA (which is generally found in a gene). The helicase activity of the polymerase causes unwinding of the double helix of DNA. This process is followed by progression in the direction from 3’ to 5’ position

The enzymes modify the primary transcript RNAs soon after the process of transcription. There are several number of RNA polymerases that make use of RNA as a template for the purpose of synthesis of a fresh strand of RNA. Take, for example, a lot of RNA viruses make use of this enzyme for replicating genetic material. RNA polymerase is included in the RNA interference pathway in several organisms.

Types of RNA

Messenger RNA (abbreviated as mRNA) is responsible for carrying information to the ribosome from the DNA. It is the coding sequence of  mRNA that is responsible for the determination of amino acid sequence present in the protein. There are however many RNAs that do not cause coding and such RNAs are known as non-coding RNAs (abbreviated as ncRNA). RNA genes can cause encoding of such ncRNAs. There are many kinds of non-coding RNAs such as Ribosomal RNA (abbreviated as rRNA) and transfer RNA (abbreviated as tRNA) and both of these types of RNAs are involved in the translation process.

As far as length is considered as a factor, there can be long RNA and small RNA. Long RNAs are general >200 nt and the small RNAs are of length <200 nt in length. Long RNAs include Messenger RNAs (abbreviated as mRNAs) and long non-coding RNA (abbreviated as lncRNA). Small RNAs include Ribosomal RNA, Piwi-interacting RNA (abbreviated as piRNA), small rDNA derived RNA (sRNA), etc. Apart from aforementioned types, there are also regulatory RNAs, RNA genomes, Double-stranded RNA, reverse transcription, small nucleolar RNAs (abbreviated as snoRNAs), etc.

Major discoveries on RNAs

There have been major research activities in respect of RNAs. In the year 1868, Friedrich Miescher discovered nucleic acids. Following this discovery, it was also found that prokaryotic cells, which lack a nucleus, also comprise of nucleic acid. In the year 1939, the scientific community first found relevant discoveries in respect of the function of the RNA as a synthesizer. In the year 1959, Severo Ochoa won Nobel prize in the field of Medicine for discovering the enzyme, which synthesizes RNA. He shared the award with Arthur Kornberg. Later, it was found that the enzyme is responsible for degradation of RNA, not for the synthesis of RNA.

In the year 1965, Robert W. Holley discovered 77 nucleotide sequence in a yeast, which made him win Nobel Prize in Medicine in the year 1968, which he shared with Marshall Nirenberg and Har Gobind Khorana. In the 1970s, reverse transcriptase and retroviruses were found, which proved that enzymes have the capability to copy RNA into DNA. Renato Dulbecco, Howard Temin, and David Baltimore worked extensively in this area and were eventually awarded Nobel prize in the year 1975. Water Friers, along with his teammates, made a successful determination of a complete RNA virus genome nucleotide sequence.

RNA splicing and introns were discovered in the year 1977. They were discovered in mammalian viruses as well as in cellular genes, which made Richard Roberts and Philip Sharp a Nobel prize in the year 1993. In the 1980s, Ribozymes, which are actually catalytic RNA molecules, were discovered that lead Sidney Altman and Thomas Cech to win Nobel Prize in the year 1989.

Contemporary research on RNA

The community of scientists has gone a long way ever since the discovery of RNA and have undertaken several scientific experiments on the same. In the year 2015, RNA and DNA organic compounds such as uracil, thymine, cytosine, etc were created in outer space conditions with the help of chemicals like pyrimidine found in meteorites.