Discover the three differences between DNA and RNA

DNA vs RNA: comparison and differences

In all living organisms, the material containing the information that is transmitted from one generation to another consists of nucleic acids called deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). But what exactly are they?

DNA and RNA: What are DNA and RNA?

DNA and RNA: Differences

• First of all, the nucleotides of DNA and RNA are different: in DNA, in fact, pentose sugar is deoxyribose, while in RNA it is ribose, which has one more oxygen atom. Moreover, in DNA the nitrogen bases are adenine, cytosine, guanine and thymine while in RNA instead of thymine there is the uracil base.
• DNA consists of two filaments running in opposite directions (antiparallel), thus forming a double helix structure in which the two polynucleotide chains are held together by hydrogen bonds between the respective nitrogen bases. The ANN instead is composed of a single filament.
• The DNA is the repository of the genetic information, while the RNA participates in the synthesis of proteins and in the transmission of the information contained in the DNA.

The role of DNA and its types

DNA is the repository of the instructions necessary for the growth, development and reproduction of each individual, inherited from parents to their descendants. It is contained in the nuclei of our individual cells, organized in chromosomes: each cell contains 23 pairs of chromosomes.

There are different types of DNA:

• A-DNA
  It is found at a humidity of 75%. In an environment where there is a higher salt concentration or ionic concentrations, such as K+, Na+, Cs+ or in a state of dehydration it endures in a form that contains 11 nucleotide pairs with a rise of 2.56A0  vertically per base pair. It has the broadest helical diameter amongst all DNA forms – 23A0 DNA which is a typical helix that is right-handed with a rotation of 32.70 per base pair. 
• B-DNA
  It is found at a humidity of 9.25 and a low salt concentration or ionic strength. It has 10 base pairs per turn from the helix axis. There is a distance of 3.4A0 with a helical diameter of 20A0. The Watson-Crick’s double helix model is defined as a B-form of DNA.
• C-DNA
  It is observed at a humidity of 66% and in the occupancy of a few ions such as Lithium(Li+). It closely has 9.33 base pairs for every turn. The diameter of the helix is about 19A0and the vertical rises for every base pair for the right-handed helix is 3.320.
• D-DNA
  It is observed rarely as an extreme variant. The 8 base pairs are titled negatively from the helix axis with an axial rise if about 3.03A0
• Z-DNA
  It is found in an environment with a very high salt concentration. Unlike the A, B, and C type of DNA, it is a left-handed helical structure. The backbone is arranged in a zig-zag pattern formed by the sugar-phosphate linkage wherein the recurrent monomer is the dinucleotide in contrast to the mononucleotide which is observed in alternate forms.

The role of RNA and its types

RNA is a ribonucleic acid that helps in the synthesis of proteins in our body.  It is usually obtained from the DNA molecule. Esistono in particolare diversi tipi di RNA:

•  tRNA – Transfer RNA
  The transfer RNA is held responsible for choosing the correct protein or the amino acids required by the body in-turn helping the ribosomes. It is located at the endpoints of each amino acid. This is also called as soluble RNA and it forms a link between the messenger RNA and the amino acid.
• rRNA-Ribosomal RNA
  The rRNA is the component of the ribosome and is located within the cytoplasm of a cell, where ribosomes are found. The Ribosomal RNA is primarily involved in the synthesis and translation of mRNA into proteins in all living organisms.
• mRNA – Messenger RNA
  As the name itself tells, this RNA is responsible for carrying the genetic material to the ribosomes and insists as to what kind of proteins is required by the body. Hence it is called messenger RNA. Usually, this m-RNA is involved in the process of transcription or during the protein synthesis process.

The importance of proteins

Proteins play a critical role in how cells successfully meet the challenges of living. Cells use proteins to maintain their shape and to speed up important chemical reactions such as photosynthesis and respiration.

A cell will not live long if it cannot reliably create the proteins that it needs for survival.