nukleinsýra

Nukleinsýra is the Icelandic term for nucleic acid. Nucleic acids are complex macromolecules essential for all known forms of life. They are polymers made up of repeating nucleotide subunits. Each nucleotide consists of three components: a nitrogenous base, a five-carbon sugar, and one or more phosphate groups. The two primary types of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).

DNA carries the genetic instructions for the development, functioning, growth, and reproduction of all known organisms and many viruses. Its structure is a double helix, with two strands wound around each other. The sequence of nitrogenous bases (adenine, guanine, cytosine, and thymine) along the DNA molecule encodes genetic information.

RNA plays various roles in gene expression and regulation. Unlike DNA, RNA is typically single-stranded and its sugar is ribose instead of deoxyribose. The nitrogenous bases in RNA are adenine, guanine, cytosine, and uracil (which replaces thymine). Key types of RNA include messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA), each with specific functions in protein synthesis.

The study of nucleic acids is fundamental to molecular biology and genetics, providing insights into heredity, disease, and the very mechanisms of life.