{"id":7757,"date":"2019-05-22T16:00:19","date_gmt":"2019-05-22T16:00:19","guid":{"rendered":"http:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/dna_-deoxyribonucleic_acid\/"},"modified":"2019-05-22T16:00:19","modified_gmt":"2019-05-22T16:00:19","slug":"dna_-deoxyribonucleic_acid","status":"publish","type":"post","link":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/dna_-deoxyribonucleic_acid\/","title":{"rendered":"DNA (deoxyribonucleic acid)"},"content":{"rendered":"<p>The self-replicating molecule forming the hereditary material as chromosomes in the nuclei of eukaryotes and as strands in prokaryotes. &nbsp;It is a nucleic acid made up of two chains or strands of nucleotides composed of deoxyribose sugar and the bases adenine, cytosine, guanine and thymine (referred to as &#8216;nucleobases&#8217;). &nbsp;The two strands wind round each other and are linked by hydrogen bonds between specific complementary bases to form a spiral ladder-shaped molecule called the double helix. &nbsp;DNA functions in three general ways:&nbsp;1. replication (or DNA synthesis):&nbsp;during cell division (i.e., mitosis), DNA uncoils, with each strand creating a new partner from the surrounding material. This amounts to &#8216;unzipping&#8217; the double strand down the middle by means of relatively simple chemical reactions, with the other half of each new single strand being recreated by &#8216;drowning&#8217; each half in a &#8216;soup&#8217; of the four nucleases. &nbsp;Errors in replication can give rise to mutations; 2. sexual reproduction:&nbsp;each parent contributes one of the two strands in the DNA of the offspringy; and 3. protein production:&nbsp;DNA governs the production of proteins, as well as other molecules essential to cell functioning. &nbsp;In fact, the sequence of nucleotides along a DNA strand defines a protein, and the relationship between this sequence and the amino acid sequence of the protein is the result of cellular rules of translation. &nbsp;Together, these rules are referred to as the &#8216;genetic code&#8217;. &nbsp;In many organisms, only a small part of the nucleotide sequence seems to encode for protein. &nbsp;The remaining parts of the sequence, called &#8216;junk DNA&#8217;, estimated to constitute about 95% of the human genome, may have a number of (as yet unknown) functions, one of which is to regulate the production of protein during development (and are thus named &#8216;regulatory sequences&#8217;). &nbsp;In now seems evident that DNA includes from genes at least eight retroviruses that become incorporated into human DNA during our evolution. &nbsp;It is thought that these viral genes in DNA have important functions in human reproduction, even though they are alien to our genetic ancestry. &nbsp;DNA was first isolated as a distinct molecule by the Swiss physician and biologist <a href=\"http:\/\/www.dnaftb.org\/15\/bio.html\" class=\"cc-route-enabled\" data-editable-link=\"http:\/\/www.dnaftb.org\/15\/bio.html&amp;target=_self\" target=\"_self\" rel=\"noopener noreferrer\">Friedrich Miescher<\/a> (1844-1895) in 1869. &nbsp; &nbsp;&nbsp;<\/p>\n<p>See <a href=\"acrosome\">Acrosome<\/a>, <a href=\"adenine\">Adenine<\/a>, <a href=\"allele\">Allele<\/a>, <a href=\"amino_acids\">Amino acids<\/a>, <a href=\"carcinogen\">Carcinogen<\/a>, <a href=\"cell\">Cell<\/a>, <a href=\"central_dogma_of_molecular_biology\">Central dogma of molecular biology<\/a>, <a href=\"chromatid\">Chromatid<\/a>, <a href=\"chromatin\">Chromatin<\/a>, <a href=\"chromosome\">Chromosome<\/a>, <a href=\"competence_-embryology-\">Competence (embryology)<\/a>, <a href=\"copying_errors\">Copying errors<\/a>, <a href=\"cytosine\">Cytosine<\/a>, <a href=\"deoxyribose\">Deoxyribose<\/a>, <a href=\"dna_double_helix\">DNA double helix<\/a>, <a href=\"eukaryote_cell_-or_organism-\">Eukaryote cell (or organism)<\/a>, <a href=\"gene\">Gene<\/a>, <a href=\"genome\">Genome<\/a>, <a href=\"guanine\">Guanine<\/a>, <a href=\"mecp2_gene\">MECP2 gene<\/a>, <a href=\"methylation\">Methylation<\/a>, <a href=\"mitosis\">Mitosis<\/a>, <a href=\"molecular_biology\">Molecular biology<\/a>, <a href=\"mosaicism\">Mosaicism<\/a>, <a href=\"mutation_-biology-\">Mutation (biology)<\/a>, <a href=\"mutagens\">Mutagens<\/a>, <a href=\"myoblast\">Myoblast<\/a>, <a href=\"nucleic_acid\">Nucleic acid<\/a>, Nucleiod, <a href=\"nucleotide\">Nucleotide<\/a>, <a href=\"prokaryote_cell_-or_organism-\">Prokaryote cell (or organism)<\/a>, <a href=\"protein-folding_problem\">Protein-folding problem<\/a>, <a href=\"purines\">Purines<\/a>, <a href=\"pyrimidines\">Pyrimidines<\/a>, <a href=\"retrovirus\">Retrovirus<\/a>, <a href=\"ribose\">Ribose<\/a>, <a href=\"recombinant_dna_-rdna-\">Recombinant DNA (rDNA)<\/a>, Regulatory (or regulator) genes, <a href=\"structural_genes\">Structural genes<\/a>, <a href=\"thymine\">Thymine<\/a>, Translation (genetics) <\/p>\n<p><\/p>\n<p><\/p>\n<p><\/body><\/html><\/p>\n","protected":false},"excerpt":{"rendered":"<p>The self-replicating molecule forming the hereditary material as chromosomes in the nuclei of eukaryotes and as strands in prokaryotes. &nbsp;It is a nucleic acid made up of two chains or strands of nucleotides composed of deoxyribose sugar and the bases adenine, cytosine, guanine and thymine (referred to as &#8216;nucleobases&#8217;). &nbsp;The two strands wind round each &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/dna_-deoxyribonucleic_acid\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;DNA (deoxyribonucleic acid)&#8221;<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[2],"class_list":["post-7757","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-glossary","entry"],"_links":{"self":[{"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/posts\/7757","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/comments?post=7757"}],"version-history":[{"count":0,"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/posts\/7757\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/media?parent=7757"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/categories?post=7757"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lancaster.ac.uk\/fas\/psych\/glossary\/wp-json\/wp\/v2\/tags?post=7757"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}