DNADoppelstränge

DNADoppelstränge refers to the double-stranded structure of deoxyribonucleic acid. DNA is a molecule that carries the genetic instructions for the development, functioning, growth, and reproduction of all known organisms and many viruses. It is composed of two long chains of nucleotide units, where each unit consists of a deoxyribose sugar, a phosphate group, and one of four nitrogenous bases: adenine (A), guanine (G), cytosine (C), and thymine (T). These two strands are held together by hydrogen bonds between the bases. Adenine always pairs with thymine, forming two hydrogen bonds, while guanine always pairs with cytosine, forming three hydrogen bonds. This specific base pairing is known as complementary base pairing and is crucial for DNA replication and transcription. The two strands run in opposite directions, a property called antiparallel orientation. One strand runs in the 5' to 3' direction, and the other runs in the 3' to 5' direction. This helical structure, with the sugar-phosphate backbone on the outside and the bases on the inside, provides stability and a mechanism for accurate copying of genetic information.