DNA replication is a semiconservative process in which the two strands are separated and new complementary strands are generated independently, resulting in two exact copies of the original DNA molecule. Each copy thus contains one strand that is derived from the parent and one newly synthesized strand. Replication begins at a specific point on a chromosome called an origin, proceeds in both directions along the strand, and ends at a precise point. In the case of circular chromosomes, the end is reached automatically when the two extending chains meet, at which point specific proteins join the strands. DNA polymerases cannot initiate replication at the end of a DNA strand; they can only extend preexisting oligonucleotide fragments called primers. Therefore, in linear chromosomes, special mechanisms initiate and terminate DNA synthesis to avoid loss of information. The initiation of DNA synthesis is usually preceded by synthesis of a short RNA primer by a specialized RNA polymerase called primase. Following DNA replication, the initiating primer RNAs are degraded.<\/p>\n\n\n\n
The two DNA strands are replicated in different fashions dictated by the direction of the phosphodiester bond. The leading strand is replicated continuously by adding individual nucleotides to the 3\u2032 end of the chain. The lagging strand is synthesized in a discontinuous manner by laying down short RNA primers and then filling the gaps by DNA polymerase, such that the bases are always added in the 5\u2032 to 3\u2032 direction. The short RNA fragments made during the copying of the lagging strand are degraded when no longer needed. The two newly synthesized DNA segments are joined by an enzyme called DNA ligase. In this way, replication can proceed in both directions, with two leading strands and two lagging strands proceeding outward from the origin.<\/p>\n","protected":false},"excerpt":{"rendered":"
Basic mechanisms DNA replication is a semiconservative process in which the two strands are separated and new complementary strands are generated independently, resulting in two exact copies of the original DNA molecule. Each copy thus contains one strand that is derived from the parent and one newly synthesized strand. Replication begins at a specific point on […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[],"class_list":["post-1904","post","type-post","status-publish","format-standard","hentry","category-nucleic-acids"],"Cooking_time":"","jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/cake.appscodestudio.com\/index.php\/wp-json\/wp\/v2\/posts\/1904","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cake.appscodestudio.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cake.appscodestudio.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cake.appscodestudio.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/cake.appscodestudio.com\/index.php\/wp-json\/wp\/v2\/comments?post=1904"}],"version-history":[{"count":2,"href":"https:\/\/cake.appscodestudio.com\/index.php\/wp-json\/wp\/v2\/posts\/1904\/revisions"}],"predecessor-version":[{"id":1931,"href":"https:\/\/cake.appscodestudio.com\/index.php\/wp-json\/wp\/v2\/posts\/1904\/revisions\/1931"}],"wp:attachment":[{"href":"https:\/\/cake.appscodestudio.com\/index.php\/wp-json\/wp\/v2\/media?parent=1904"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cake.appscodestudio.com\/index.php\/wp-json\/wp\/v2\/categories?post=1904"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cake.appscodestudio.com\/index.php\/wp-json\/wp\/v2\/tags?post=1904"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}