THE DNA THREADS

<body topmargin=0 leftmargin=0 marginheight=0 marginwidth=0> <table cellpadding=0 cellspacing=0 border=0><tr> <td valign="top" colspan=2 height=28 BGCOLOR="#006699" TEXT="#080000"> <div> <FONT SIZE="2" COLOR="#FFFBF0" FACE="Arial" ><B>CHEMISTRY SCHOOL</B></FONT><FONT SIZE="1" COLOR="#FFFBF0" FACE="Arial" ><B> </B></FONT><FONT SIZE="1" COLOR="#FFFFCC" FACE="Arial" ><B>   </B></FONT><B>                     </B><FONT SIZE="1" COLOR="#FFFFCC" FACE="Arial" ><B> </B></FONT><A HREF="index.htm" TARGET="_top" TITLE="CHEMISTRY SCHOOL"><U>HOME PAGE - INDEX TO THE LESSONS</U></A> <B>                           </B>PAGE  7     THE DNA THREADS <A NAME="the_dna_threads"><IMG BORDER="0" SRC="1x1.gif" HEIGHT="1" ALIGN="bottom" WIDTH="1" HSPACE="0" VSPACE="0" ></A></div> <bR> <div> </div> </td> </tr><tr> <td valign="top" width=210 BGCOLOR="#66CCCC" TEXT="#080000"> <div> <A HREF="our_nucleic_acids_.htm" TARGET="_top" TITLE="OUR NUCLEIC ACIDS"><U>" OUR NUCLEIC ACIDS "</U></A></div> <bR> <div> TABLE OF CONTENTS</div> <div> <A HREF="guanine.htm" TARGET="_top" TITLE="GUANINE"><U>PAGE 1           </U></A><A HREF="guanine.htm" TARGET="_top" TITLE="GUANINE"><U><B>G U A N I N E</B></U></A></div> <div> <A HREF="human_adenine.htm" TARGET="_top" TITLE="ADENINE"><U>PAGE 2          </U></A><A HREF="human_adenine.htm" TARGET="_top" TITLE="ADENINE"><U><B> A D E N I N E</B></U></A></div> <div> <A HREF="human_cytosine.htm" TARGET="_top" TITLE="CYTOSINE"><U>PAGE 3         </U></A><A HREF="human_cytosine.htm" TARGET="_top" TITLE="CYTOSINE"><U><B>C Y T O S I N E</B></U></A></div> <div> <A HREF="different_thymines.htm" TARGET="_top" TITLE="THYMINE"><U>PAGE 4          </U></A><A HREF="different_thymines.htm" TARGET="_top" TITLE="THYMINE"><U><B>T H Y M I N E</B></U></A></div> <div> <A HREF="different_uracils.htm" TARGET="_top" TITLE="URACIL"><U>PAGE 5           </U></A><A HREF="different_uracils.htm" TARGET="_top" TITLE="URACIL"><U> </U></A><A HREF="different_uracils.htm" TARGET="_top" TITLE="URACIL"><U><B>U R A C I L</B></U></A></div> <div> <A HREF="chromatin_chromatids_chromosomes_nucleic_acids.htm" TARGET="_top" TITLE="NUCLEIC ACIDS and GENES"><U>PAGE 6      NUCLEIC ACIDS</U></A></div> <div> <A HREF="the_dna_threads.htm" TARGET="_top" TITLE="THE DNA THREADS"><U>PAGE 7   THE DNA THREADS</U></A></div> <div> <A HREF="dna_rna_comparison.htm" TARGET="_top" TITLE="DNA RNA"><U>PAGE 8            DNA ~ RNA</U></A></div> <div> <A HREF="natural_shapes.htm" TARGET="_top" TITLE="NATURAL SHAPES"><U>PAGE 9    NATURAL SHAPES</U></A></div> <div> <A HREF="purines_and_pyrimidines.htm" TARGET="_top" TITLE="PURINES"><U>PAGE 10         PURINES +</U></A></div> <div> <A HREF="genome_research.htm" TARGET="_top" TITLE="GENOME RESEARCH"><U>PAGE 11       RESEARCH</U></A></div> <bR> <DIV ALIGN="LEFT"></DIV> <div> <A HREF="the_dna_threads_m.htm#the_fosfate_strands_1" TARGET="TRLX_Middle" TITLE="THE DNA THREADS"><U><IMG SRC="15d8465b0.gif" border=0 width="70" height="91" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></U></A></div> </td> <td valign="top" height=452 BGCOLOR="#FFFFFF" TEXT="#080000"> <div> <A HREF="#the_fosfate_strands_1" TITLE="THE DNA THREADS"><U><IMG SRC="1aef209c0.gif" border=0 width="544" height="412" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></U></A></div> <div> <TABLE BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="541" BORDERCOLORLIGHT="#C0C0C0" BORDERCOLORDARK="#808080" FRAME="BOX" RULES="ALL" ALIGN="BOTTOM" HSPACE="0" VSPACE="0" > <tR> <tD VALIGN=TOP HEIGHT= 586 ><NOBR><div> <FONT SIZE="1" COLOR="#FFFFFF" FACE="Arial" >X</FONT>   <A NAME="the_fosfate_strands_1"><IMG BORDER="0" SRC="1x1.gif" HEIGHT="1" ALIGN="bottom" WIDTH="1" HSPACE="0" VSPACE="0" ></A></div> <div>   THE DRAWING, ON THE RIGHT, SHOWS >>></div> <div>   HOW THE THREE, RIBOSE-FOSFATE STRANDS,</div> <div>   COIL AROUND,THE  PLATE-LIKE, NUCLEIC ACIDS</div> <div>   THE PLATE-LIKE, NUCLEIC ACIDS, ARE ALIGNED,</div> <div>   ONE,DIRECTLY BELOW THE OTHER, IN THE DRAWING,</div> <div>   BECAUSE, THE SECTIONS, OF DNA, ARE STRETCHED,</div> <div>   APART, STAINED AND STRAIGHTENED, BEFORE, </div> <div>   AN X-RAY DIFFRACTION STUDY, IS MADE.</div> <div>   THE ORIGINAL DRAWING, WAS MADE, BY TRACING,</div> <div>   THE OUTLINE OF THE ROUGH  IMAGES, IN AN X-RAY</div> <div>   DIFFRACTION STUDY, BY DR.ROSALIND FRANKLIN, </div> <div>   OF HUMAN  DNA, ONTO A PIECE OF CLEAR FILM.</div> <div>   THE DRAWING OF OUR HUMAN DNA,ON THE RIGHT,</div> <div>   IS AN ENLARGEMENT, OF THE ORIGINAL DRAWING, </div> <div>   WHICH IS ONLY, 2 CM X 3 CM. IN SIZE.</div> <bR> <bR> <bR> <div>                           <A HREF="the_dna_threads_m.htm" TITLE="THE DNA THREADS"><U>BACK TO TOP</U></A></div> </NOBR></tD> <tD VALIGN=TOP><NOBR><div> <TABLE BORDER="1" CELLPADDING="0" CELLSPACING="0" WIDTH="185" BORDERCOLORLIGHT="#FF9980" BORDERCOLORDARK="#808080" FRAME="BOX" RULES="ALL" ALIGN="BOTTOM" HSPACE="0" VSPACE="0" > <tR> <tD VALIGN=TOP BGCOLOR=#EEEEEE HEIGHT= 245 ><NOBR><div> <IMG SRC="15d2b2ee0.gif" border=0 width="178" height="238" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></div> </NOBR></tD> </tR> </TABLE></div> <DIV ALIGN="LEFT"></DIV> <div> THE FOSFATE STRANDS</div> <div> THAT COIL AROUND OUR</div> <div> NUCLEIC ACIDS</div> <bR> </NOBR></tD> </tR> </TABLE></div> <bR> </td> </tr></table></body>