Deoxyribonucleic acid or just DNA is the most important molecule in living organisms. It contains the instructions and code, which all organism need to live, develop and in the end, to reproduce. The instructions, which are passed down from each parent to their kids, can be found inside every living cell.
The Structure of DNA
DNA is composed of nucleotides, which are made up of a phosphate group, a nitrogen base and a sugar group. There are four distinctive nitrogen bases: adenine (A), guanine (G), cytosine (C) and thymine (T). The specific order of nitrogen basis determines the genetic code of all living creatures or the DNA’s instructions. There is another type of nucleic acid, RNA or ribonucleic acid, which is responsible for the translation of the genetic information from DNA to proteins. The human genome is composed of about 20, 000 genes and around 3 billion nitrogen bases.
Moreover, nucleotides are attached to each other and they form two long and thin spiral strands with a double helix structure. On the outside of the strand, there are sugar molecules and phosphates and the bases are on the inside. Each base has its pair from one strand to another, whereas adenine (A) is always in pair with thymine (T), and cytosine (C) with guanine (G). Humans have exactly 23 pairs of chromosomes located inside the nucleus of the cell. DNA molecule is packed to form the chromosomes so that it can fit the cell.
The Discovery Of DNA
Discovery of the DNA is attributed to biochemist Frederich Miescher, who first observed it in 1869. After many years, in 1953, Francis Crick, James Watson, Rosalind Franklin and Maurice Wilkins explained the structure and the importance of the DNA molecule. They figured it out that the DNA structure is a double helix and that it carries all biological information. However, only Crick, Watson and Wilkins were awarded for the discovery. They received the Nobel Prize in 1962 for medicine.