RNA or ribonucleic acid is a polynucleotide compound as in DNA, but there are differences between RNA and DNA. RNA is the result of transcription of DNA, so the position of RNA is as polymer and much shorter compared to DNA.
DNA is commonly found in the nucleus, while RNA is found in the cytoplasm especially in the ribosome, but there are also those found in the nucleus. RNA and DNA are nucleic acids along with carbohydrates and proteins.
RNA molecules play an important role in the process of genetic expression contained in DNA through protein synthesis. Therefore, the molecular content of RNA is not fixed because it is determined by the activity of protein synthesis, unlike the levels of DNA molecules that are fixed and not affected by the activity of protein synthesis.
Unlike DNA, RNA molecules are also unable to replicate and are not genetic material that can bequeath traits to their offspring. But in some viruses, such as reoviruses, influenza viruses and others, RNA is the genetic material.
Ribonucleic acid definition
Ribonucleic acid (RNA) is a nucleotide chain present in cells of all life. These chains have a number of important functions for living organisms, ranging from regulation of gene expression to help with gene copying.
Severo Ochoa, Robert Holley, and Carl Woese all played an important role in finding RNA and understanding how it works, and more research is constantly being done.
Many people are familiar with deoxyribonucleic acid (DNA), a nucleic acid often referred to as the “building block of life” because it contains genetic material for the parents of such organisms. RNA is just as important, even if it is less well known, because it plays an important role in helping DNA to copy and express genes, and to transport genetic material inside cells. RNA also has a number of independent functions that are no less important.
Ribonucleic Acid Types
RNA is present in nature in a variety of types. As a genetic material, RNA is in the form of a pair of ribbons (double-stranded RNA, dsRNA). Classical molecular genetics teach, in eukaryotes there are three types of RNA involved in the process of protein synthesis:
- Messenger-RNA (mRNA), synthesized by RNA polymerase I.
- RNA-ribosome (ribosomal-RNA, rRNA), synthesized with RNA polymerase II
- RNA-transfer (transfer-RNA, tRNA), synthesized with RNA polymerase III.
Messenger RNA (mRNA) brings information about the sequence of proteins to the ribosome, which is the synthesis plant of proteins in cells. This RNA sheet is encoded so that each nucleotide (one codon) represents one amino acid.
In eukaryotic cells, the initially formed mRNA (pre-mRNA) becomes a mature mRNA when transcribed from its original DNA through the removal of the intron – a pre-mRNA fragment that cannot be encoded. This mRNA is then transported from the nucleus to the cytoplasm where it binds to the ribosome and is converted into its own protein with the help of tRNA.
In prokaryotic cells that do not have the nucleus and cytoplasm, mRNA can bind to ribosomes when undergoing transcription from DNA. After a certain period of time, this sequence is broken down into nucleotide components with the help of ribonuclease.
Transfer RNA (tRNA) is a small RNA chain consisting of 80 nucleotides that carry one specific amino acid to a long chain of polypeptides at the ribosome site of protein synthesis during the mRNA translation process. These molecules have amino acid binding sites as well as anticode regions for the identification of codons that bind to specific sequences in the mRNA chain through hydrogen bonds.
Ribosome RNA (rRNA) is a ribosome component that has the ability to catalyze. Ribosomes in eukaryotic organisms have four types of rRNA molecules: 18S, 5.8S, 28S and 5S. Three of these rRNA molecules are synthesized in the nucleus, while others are produced elsewhere.
In the cytoplasm, ribosome and RNA proteins combine to form a nucleoprotein called a ribosome. These ribosomes bind to mRNA and synthesize proteins. Multiple ribosomes can be connected with one mRNA at a time.
Ribonucleic Acid Function
Below is the function of RNA, among others as follows:
- As a storage of information
- As an intermediary between DNA and proteins in a process of genetic expression because it applies to living organisms.
Ribonucleic Acid Structure
Below are the structures of RNA, including the following:
- D-Ribose Sugar
- Nitrogen Bases
RNA consists of polyribonucleotide chains that bases are usually adenine, guanine, uracil, and cytosine. RNA is in the nucleus or cytoplasmic cells. This variety of RNA forms are also more than DNA. This RNA has a molecular weight of between 25,000 and several million.
Generally the RNA contains a single polynucleotide chain, but also this usual chain folds into a double helical region containing base pairs A:U and G:C.
RNA molecules have different shapes to DNA. RNA has a single ribbon shape and is also not twisted. Each RNA band is a polynucleotide composed of many ribonucleotides. Each ribonucleotide is composed of Ribose sugar, nitrogen bases as well as phosphoric acid.
RNA nitrogen base is divided into two, namely purine base and pyrimidine base. Purine bases are the same as DNA composed of adenine (A) and guanine (G), while the pyrimidine base is composed of cytosine (C) and uracil (U).
The backbone of this RNA is composed of rows of ribose as well as phosphates. Ribonucleotide RNA is freely present in the nucleoplasm with the form of nucleosides of the triphosphate, for example
- Adenosine phosphate (ATP),
- Guanosine triphosphate (GTP), Cystidine Triphosphate (CTP), and
- Uridine Triphosphate (UTP).
RNA is syntheticized by DNA in the cell nucleus using that DNA as a mold.