FAQ
Szukaj
Użytkownicy
Grupy
Galerie
Rejestracja
Profil
Zaloguj
Zaloguj się, by sprawdzić wiadomości
Forum www.legendsofshaman.fora.pl Strona Główna
->
News
Użytkownik
Temat
Treść wiadomości
Emotikony
Więcej Ikon
Opcje
HTML:
NIE
BBCode
:
TAK
Uśmieszki:
TAK
Wyłącz BBCode w tym poście
Wyłącz Uśmieszki w tym poście
Kod potwierdzający: *
Skocz do:
Wybierz forum
Server
----------------
News
Tutorzy i Game Masterzy
Multimedia
Poradniki
Grafiki
Inne
----------------
Hyde Park
Przegląd tematu
<table border="0" cellpadding="3" cellspacing="1" width="89%" align="center" class="forumline"> <tr> <th class="thCornerL" width="22%" height="26">Autor</th> <th class="thCornerR">Wiadomość</th> </tr> <tr> <td width="22%" align="left" valign="top" class="row1"><span class="name"><a name=""></a><b>zngmqk04</b></span></td> <td class="row1" height="28" valign="top"><table width="100%" border="0" cellspacing="0" cellpadding="0"> <tr> <td width="100%"><img src="http://picsrv.fora.pl/Play/images/icon_minipost.gif" width="12" height="9" alt="Post" title="Post" border="0" /><span class="postdetails">Wysłany: Czw 12:37, 24 Mar 2011<span class="gen"> </span> Temat postu: Transcription initiation is ed hardy bags</span></td> </tr> <tr> <td colspan="2"><hr /></td> </tr> <tr> <td colspan="2"><span class="postbody">In bacteria, transcription begins with the binding of RNA polymerase to the promoter in DNA. RNA polymerase is a core enzyme consisting of five subunits: 2 &alpha; subunits,<a href="http://www.ed-hardyshirt.com" target="_blank" class="postlink">ed hardy bags</a> 1 &beta; subunit, 1 &beta;' subunit, and 1 &omega; subunit. At the start of initiation, the core enzyme is associated with a sigma factor that aids in finding the appropriate -35 and -10 base pairs downstream of promoter sequences.[citation needed] <br />Transcription initiation is more complex in eukaryotes. Eukaryotic RNA polymerase does not directly recognize the core promoter sequences. Instead, a collection of proteins called transcription factorsmediate the binding of RNA polymerase and the initiation of transcription. Only after certain transcription factors are attached to the promoter does the RNA polymerase bind to it. The completed assembly of transcription factors and RNA polymerase bind to the promoter, forming a transcription initiation complex. Transcription in the archaea domain is similar to transcription in eukaryotes. <br />One strand of the DNA,<a href="http://www.replica-rolexwatche.com" target="_blank" class="postlink">rolex daytona</a> the template strand (or noncoding strand), is used as a template for RNA synthesis. As transcription proceeds, RNA polymerase traverses the template strand and uses base pairing complementarity with the DNA template to create an RNA copy. Although RNA polymerase traverses the template strand from 3' &rarr; 5', the coding (non-template) strand and newly-formed RNA can also be used as reference points, so transcription can be described as occurring 5' &rarr; 3'. This produces an RNA molecule from 5' &rarr; 3',<a href="http://www.nike-airshoe.com" target="_blank" class="postlink">air max 2011</a>, an exact copy of the coding strand (except that thymines are replaced with uracils, and the nucleotides are composed of a ribose (5-carbon) sugar where DNA has deoxyribose (one less oxygen atom) in its sugar-phosphate backbone).[citation needed] <br />Unlike DNA replication, mRNA transcription can involve multiple RNA polymerases on a single DNA template and multiple rounds of transcription (amplification of particular mRNA), so many mRNA molecules can be rapidly produced from a single copy of a gene.[citation needed] <br />Elongation also involves a proofreading mechanism that can replace incorrectly incorporated bases. In eukaryotes,<a href="http://www.nike-airshoe.com" target="_blank" class="postlink">nike chaussures</a> this may correspond with short pauses during transcription that allow appropriate RNA editing factors to bind. These pauses may be intrinsic to the RNA polymerase or due to chromatin structure.</span></td> </tr> </table></td> </tr> <tr> <td colspan="2" height="1" class="spaceRow"><img src="http://picsrv.fora.pl/Play/images/spacer.gif" alt="" width="1" height="1" /></td> </tr> </table>
fora.pl
- załóż własne forum dyskusyjne za darmo
phpBB
© 2001, 2002 phpBB Group
Play
Graphic Theme
Regulamin
