DNA: Its building blocks

  • strict warning: Non-static method view::load() should not be called statically in /home/dvdfos0/public_html/geneticssuite/sites/all/modules/views/views.module on line 823.
  • strict warning: Declaration of views_plugin_display::options_validate() should be compatible with views_plugin::options_validate(&$form, &$form_state) in /home/dvdfos0/public_html/geneticssuite/sites/all/modules/views/plugins/views_plugin_display.inc on line 0.
  • strict warning: Declaration of views_plugin_display_block::options_submit() should be compatible with views_plugin_display::options_submit(&$form, &$form_state) in /home/dvdfos0/public_html/geneticssuite/sites/all/modules/views/plugins/views_plugin_display_block.inc on line 0.
  • strict warning: Declaration of views_plugin_display_page::options_submit() should be compatible with views_plugin_display::options_submit(&$form, &$form_state) in /home/dvdfos0/public_html/geneticssuite/sites/all/modules/views/plugins/views_plugin_display_page.inc on line 0.
  • strict warning: Declaration of views_handler_field_broken::ui_name() should be compatible with views_handler::ui_name($short = false) in /home/dvdfos0/public_html/geneticssuite/sites/all/modules/views/handlers/views_handler_field.inc on line 0.
  • strict warning: Declaration of views_handler_sort_broken::ui_name() should be compatible with views_handler::ui_name($short = false) in /home/dvdfos0/public_html/geneticssuite/sites/all/modules/views/handlers/views_handler_sort.inc on line 0.
  • strict warning: Declaration of views_handler_filter::options_validate() should be compatible with views_handler::options_validate($form, &$form_state) in /home/dvdfos0/public_html/geneticssuite/sites/all/modules/views/handlers/views_handler_filter.inc on line 0.
  • strict warning: Declaration of views_handler_filter::options_submit() should be compatible with views_handler::options_submit($form, &$form_state) in /home/dvdfos0/public_html/geneticssuite/sites/all/modules/views/handlers/views_handler_filter.inc on line 0.
  • strict warning: Declaration of views_handler_filter_broken::ui_name() should be compatible with views_handler::ui_name($short = false) in /home/dvdfos0/public_html/geneticssuite/sites/all/modules/views/handlers/views_handler_filter.inc on line 0.
  • strict warning: Declaration of views_handler_filter_many_to_one::init() should be compatible with views_handler_filter::init(&$view, $options) in /home/dvdfos0/public_html/geneticssuite/sites/all/modules/views/handlers/views_handler_filter_many_to_one.inc on line 0.
  • strict warning: Declaration of views_handler_filter_term_node_tid::value_validate() should be compatible with views_handler_filter::value_validate($form, &$form_state) in /home/dvdfos0/public_html/geneticssuite/sites/all/modules/views/modules/taxonomy/views_handler_filter_term_node_tid.inc on line 0.
  • strict warning: Declaration of views_plugin_row::options_validate() should be compatible with views_plugin::options_validate(&$form, &$form_state) in /home/dvdfos0/public_html/geneticssuite/sites/all/modules/views/plugins/views_plugin_row.inc on line 0.
  • strict warning: Declaration of views_plugin_row::options_submit() should be compatible with views_plugin::options_submit(&$form, &$form_state) in /home/dvdfos0/public_html/geneticssuite/sites/all/modules/views/plugins/views_plugin_row.inc on line 0.

Deoxyribonucleic acid (DNA) is an acid referred to as nucleic acid and contains the genetic instructions used in the development and functioning of all living organisms and some viruses. Some viruses use RNA instead of DNA. DNA molecules store genetic information that is passed from one generation to the next.

In living organisms, DNA does not usually exist as a single molecule, but instead as a tightly-associated pair of strands. Each of the strands of DNA consists of simple units called nucleotides. Each nucleotide consists of a deoxyribose sugar attached to a nitrogenous base and a phosphate. Four different bases are present in DNA: the pyrimidines adenine (A) and guanine (G) and the purines cytosine (C) and thymine (T).  

The bases

 

Single stranded DNA

A single strand (polymer) of DNA has nucleotides linked by ester bonded phosphate groups forming a sugar-phosphate backbone. The 3’ and 5’ carbons of the sugar are used to name the two ends of the stand: 3’ (three prime) end and 5’ (five prime) end. The bases project outwards from the polymer. The sequence of these four bases along the backbone encodes information that is used to synthesise proteins.

Double stranded DNA

 Two single strands of DNA are joined with hydrogen bonds between complementary bases: A with T and G with C. There are 2 hydrogen bonds between A and T and 3 between G and C. These two strands run in opposite directions to each other and are therefore anti-parallel.
 

 

 

Related articles