deoxiribonukleinsyra

Deoxiribonukleinsyra, commonly abbreviated as DNA, is a molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses. It is a long, double-stranded helix composed of repeating units called nucleotides. Each nucleotide consists of a deoxyribose sugar, a phosphate group, and one of four nitrogenous bases: adenine (A), guanine (G), cytosine (C), and thymine (T). The sequence of these bases along the DNA strand forms the genetic code.

The two strands of the DNA helix are held together by hydrogen bonds between complementary bases, with adenine always pairing with thymine, and guanine always pairing with cytosine. This specific base pairing is crucial for DNA replication, the process by which a cell makes an exact copy of its DNA before cell division. During replication, the double helix unwinds, and each strand serves as a template for the synthesis of a new complementary strand.

DNA is organized into structures called chromosomes, which are located within the nucleus of eukaryotic cells. Genes, specific segments of DNA, contain the instructions for building proteins, the workhorses of the cell that perform a vast array of functions. The process of converting the genetic information in DNA into proteins involves two main steps: transcription, where a DNA sequence is copied into a messenger RNA (mRNA) molecule, and translation, where the mRNA sequence is used to assemble a chain of amino acids, forming a protein. Understanding DNA is fundamental to fields such as genetics, molecular biology, and medicine.