DNAkedja

DNAkedja is a Swedish term that refers to a chain of deoxyribonucleotides forming a single strand of DNA. In most organisms, DNA exists as two DNAkedjor running in opposite directions and forming the characteristic double helix. Each DNAkedja comprises nucleotides, each containing a sugar (deoxyribose), a phosphate group, and a nitrogenous base (adenine, thymine, cytosine, or guanine). The backbone is the sugar–phosphate chain, and bases pair across strands by A–T and C–G, stabilized by hydrogen bonds.

Directionality is 5' to 3' along the chain, which is important for replication and transcription. The length of a single DNAkedja is measured in bases; a double-stranded molecule is measured in base pairs.

Functionally, a DNAkedja stores genetic information through its base sequence, which directs the synthesis of RNA and, ultimately, proteins. During replication, DNAkedjor are copied in a semi-conservative manner by DNA polymerases, producing two new strands complementary to the originals. Transcription uses a DNAkedja as a template to generate an RNA molecule.

In laboratory settings, single-stranded DNA is used as probes, primers for PCR, or templates for sequencing. Properties such as GC content, temperature, and ionic strength affect the stability and hybridization of DNAkedjor.

The term DNAkedja is common in Swedish biology texts; in English, the equivalent is DNA strand. See also DNA, nucleotides, double helix, replication.