What does DNA

DNA (structure)

The Deoxyribonucleic acid (DNS, or English: deoxyribonucleic acid; DNA) is a long molecule (macromolecule) known as nucleic acid referred to as. It consists of sugars, phosphate groups (with a negative charge) and so-called nucleobases. These bases are the crucial building blocks for the nucleic acid: They are called adenine, cytosine, guanine and thymine and build an essential part of the DNA, namely the ’steps’ of the rope ladder. All but thymine also appear in the structure of RNA (ribonucleic acid). The base uracil replaces the thymine here, but does not appear in the structure of the DNA.

A nucleic base as the basic building block of DNA is first connected to a pentose (2-deoxyribose, sugar molecule with five carbon atoms). The resulting nucleoside is named after the respective base: adenosine, guanosine, thymidine, uridine and cytidine. In addition, a phosphate group is now bound to the nucleoside, creating a nucleotide. It is also named after the base involved: deoxy (because it is a base in DNA) guanosine (base sugar) monophosphate (a phosphate group). Together: deoxyguanosine monophosphate.

There are four nucleotides in total, all of which are assembled as described above. The two strands of DNA are assembled from these four different nucleotides. This is why these strands are also known as polynucleotide strands. The nucleotides are linked to each other on the 3rd and 5th carbon atom, i.e. on the 3 'and 5' area. The designations 3 'and 5' refer to the carbon atoms of the pentoses, which are numbered from one to five. ’Stands for carbon atom. Therefore, a DNA strand always has a 3 'and a 5' end. It is important that these ends are opposite so that a 5 'and a 3' end can be found at each end of a double helix.

The nucleotides are arranged in such a way that the bases point to the “middle”, ie represent the rungs of the rope ladder. The bases always form the same pairs: adenine and thymine as well as guanine and cytosine.