DNAstrenge

A DNAstrenge is one of the two long polymers that compose deoxyribonucleic acid (DNA). Each strand consists of a backbone of alternating deoxyribose sugars and phosphate groups, with nitrogenous bases—adenine (A), thymine (T), cytosine (C), and guanine (G)—attached to the sugars. The two strands are antiparallel and wind together to form the double helix. Base pairing is highly specific: A pairs with T via two hydrogen bonds, and C pairs with G via three hydrogen bonds. The sequence of bases along a DNAstrenge encodes genetic information.

In most organisms, the two strands are complementary, meaning the sequence on one strand dictates the sequence on the other. The length of a DNAstrenge is measured in nucleotides or base pairs, and, in humans, the genome contains about 3.2 billion base pairs per haploid set.

DNAstrenge function is to store, transmit, and regulate genetic information. During cell division, the double helix is replicated to produce two identical copies. In replication, the strands separate at the replication fork, and new complementary strands are synthesized by DNA polymerases, producing semiconservative daughter molecules. In eukaryotes, DNAstrenge are further packaged with proteins into chromatin and chromosomes, allowing compact storage and regulation of access to genes.

Mutations and chemical modifications of DNAstrenge can alter gene function and regulation. DNAstrenge analysis is central to genetics, forensic science, and many areas of biomedical research.