{"id":692,"date":"2014-04-30T12:55:46","date_gmt":"2014-04-30T12:55:46","guid":{"rendered":"http:\/\/hyndland-sec-glasgow.blogs.rm.com\/CfE-Higher-Unit-1\/?page_id=53"},"modified":"2014-04-30T12:55:46","modified_gmt":"2014-04-30T12:55:46","slug":"structure-of-the-genome","status":"publish","type":"page","link":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsecbiohu1\/structure-of-the-genome\/","title":{"rendered":"Structure of the Genome"},"content":{"rendered":"
5 The structure of the genome<\/span>
\n The genome of an organism is its hereditary information encoded in DNA. DNA sequences that code for protein are genes.<\/span>
\n The structure of the genome \u2014 coding and non-coding sequences. A genome is made up of genes and other DNA sequences that do not code for proteins. Non-coding sequences include those that regulate transcription and those that are transcribed to RNA but are never translated. Some non-coding sequences have no known function.<\/span><\/h5>\n\n\n\n
\"PPt\"<\/a><\/td>\n\"HwrkRevisionIcon\"<\/a><\/td>\n\"MCQIcon\"<\/a><\/td>\n\"MCQIcon\"<\/a><\/td>\n\"MCQIcon\"<\/a><\/td>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Homework Sheets 1_8A<\/a><\/p>\n

Whilst we get used to considering our genome as a series of genes which code for the production of protein. In fact, in eukaryotes (though not prokaryotes) the vast majority of\u00a0the genome (~97% in humans) does not code for protein.\u00a0 This used to be considered junk DNA, having no function, but the role of these so-called non-coding sequences is beginning to be better understood.<\/p>\n

Regulation of transcription<\/strong><\/p>\n

As discussed previously<\/a>, not all genes in a cell are expressed, and so the expression of genes is regulated by proteins called transcription factors.\u00a0 These transcription factors bind to specific sequences of DNA, often at some distance from the coding portion of a gene.\u00a0 Some of the factors, called activators will\u00a0come in contact with\u00a0the\u00a0RNA ploymerase, attached at the promoter region, as the DNA strand bends, thus initiating transcription.<\/p>\n

\"19_9\"<\/a>
\nProtection <\/strong><\/p>\n

(abridged from http:\/\/en.wikipedia.org\/wiki\/Telomere)<\/h6>\n

A telomere<\/b> is a region of repetitive nucleotide sequences at each end of a, which protects the end of the chromosome from deterioration or from fusion with neighbouring chromosomes. Its name is derived from the Greek nouns telos (\u03c4\u03ad\u03bb\u03bf\u03c2<\/i>) ‘end’ and mer\u03bfs (\u03bc\u03ad\u03c1\u03bf\u03c2<\/i>, root: \u03bc\u03b5\u03c1-<\/i>) ‘part.’ For vertebrates, the sequence of nucleotides in telomeres is TTAGGG.<\/p>\n

Transcription of non-translated RNA<\/strong><\/p>\n

A number of “genes” in the genome code for RNA which does not produce proteins.\u00a0 Examples include tRNA and rRNA which are discussed elsewhere<\/a>.\u00a0 In addition, small nuclear RNAs (snRNA) are involved in the production of mature mRNA from the\u00a0primary transcript by helping to remove introns.<\/p>\n

microRNA (miRNA) are around 22 nucleotides long and are involved in regulating translation of mRNA.<\/p>\n","protected":false},"excerpt":{"rendered":"

5 The structure of the genome The genome of an organism is its hereditary information encoded in DNA. DNA sequences that code for protein are genes. The structure of the genome \u2014 coding and non-coding sequences. A genome is made up of genes and other DNA sequences that do not code for proteins. Non-coding sequences … Continue reading “Structure of the Genome”<\/span><\/a><\/p>\n","protected":false},"author":2454,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"open","ping_status":"open","template":"","meta":{"footnotes":""},"class_list":["post-692","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsecbiohu1\/wp-json\/wp\/v2\/pages\/692","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsecbiohu1\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsecbiohu1\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsecbiohu1\/wp-json\/wp\/v2\/users\/2454"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsecbiohu1\/wp-json\/wp\/v2\/comments?post=692"}],"version-history":[{"count":0,"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsecbiohu1\/wp-json\/wp\/v2\/pages\/692\/revisions"}],"wp:attachment":[{"href":"https:\/\/blogs.glowscotland.org.uk\/gc\/hyndsecbiohu1\/wp-json\/wp\/v2\/media?parent=692"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}