OUR GENES and DNA

<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="#FFFFFF" FACE="Arial" ><B>CHEMISTRY SCHOOL</B></FONT><FONT SIZE="1" COLOR="#FFFFCC" FACE="Arial" ><B>                    </B><B> </B></FONT><A HREF="index.htm" TARGET="_top" TITLE="CHEMISTRY SCHOOL"><U>HOME PAGE - INDEX TO THE LESSON</U></A><A HREF="index.htm" TARGET="_top" TITLE="CHEMISTRY SCHOOL"><U>S</U></A><B>                   </B>PAGE 2          HUMAN GENOME REFERENCE</div> <div> <A HREF="what_is_a_helix.htm" TARGET="_top" TITLE="WHAT IS A HELIX AND WHAT IS RNA DNA ?"><U>WHAT IS A HELIX AND WHAT IS RNA & DNA ?</U></A>   |   <B>OUR GENES and DNA</B>   |   <A HREF="what_is_dna.htm" TARGET="_top" TITLE="WHAT IS DNA ?"><U>WHAT IS DNA ?</U></A>   |   <A HREF="ladder_concepts.htm" TARGET="_top" TITLE="TWISTED LADDERS"><U>TWISTED LADDERS</U></A></div> <div> </div> </td> </tr><tr> <td valign="top" width=212 BGCOLOR="#FFCC66" TEXT="#080000"> <div> ? WHAT IS A DOUBLE HELIX</div> <div>     AND WHAT IS RNA & DNA ?</div> <div>     </div> <div>      TABLE OF CONTENTS</div> <div> <A HREF="what_is_a_helix.htm" TARGET="_top" TITLE="WHAT IS A HELIX AND WHAT IS RNA DNA ?"><U>PAGE 1   WHAT IS A HELIX ?</U></A></div> <div> <A HREF="our_genes_and_dna_m.htm#our_genes" TARGET="TRLX_Middle" TITLE="OUR GENES and DNA"><U>PAGE 2   OUR GENES & DNA</U></A><A HREF="our_genes_and_dna_m.htm#our_genes" TARGET="TRLX_Middle" TITLE="OUR GENES and DNA"><U>  </U></A></div> <div> <A HREF="what_is_dna.htm" TARGET="_top" TITLE="WHAT IS DNA ?"><U>PAGE 3   DNA, WHAT IS DNA ?</U></A></div> <div> <A HREF="ladder_concepts.htm" TARGET="_top" TITLE="TWISTED LADDERS"><U>PAGE 4  TWISTED LADDERS</U></A></div> <bR> <bR> <bR> <bR> <bR> <bR> <div>        KROH  MOH  SOHM  S</div> <div>        CHRO - MO - SOME S </div> <bR> <div>           CHROMOSOMES</div> <bR> <div>  </div> <bR> <bR> <bR> <bR> </td> <td valign="top" height=452 BGCOLOR="#FFFFFF" TEXT="#080000"> <div> <I><B>OUR GENES...IN THE DNA.....IN OUR CHROMOSOMES            </B></I><I><B> <A NAME="our_genes"><IMG BORDER="0" SRC="1x1.gif" HEIGHT="1" ALIGN="bottom" WIDTH="1" HSPACE="0" VSPACE="0" ></A></B></I></div> <div> <TABLE BORDER="0" CELLPADDING="2" CELLSPACING="1" WIDTH="539" BORDERCOLORLIGHT="#C0C0C0" BORDERCOLORDARK="#808080" FRAME="BOX" RULES="ALL" ALIGN="BOTTOM" HSPACE="0" VSPACE="0" > <tR> <tD VALIGN=TOP HEIGHT= 209 ><NOBR><div> <IMG SRC="1bb02fcb0.gif" border=0 width="303" height="203" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></div> </NOBR></tD> <tD VALIGN=TOP><NOBR><bR> <div> EACH OF OUR CHROMOSOMES,</div> <div> IS MADE OF TWO, VERY LONG, </div> <div> COILED CORDS, OF HUMAN GENES,</div> <div> ON THE LEFT, IS A PICTURE,</div> <div> OF HOW, OUR CHROMOSOMES LOOK.</div> <bR> <div> THEY ARE HELD TOGETHER, </div> <div> IN THE MIDDLE, BY A THICK RING, </div> <div> CALLED A CENTROMERE, MADE OF </div> <div> CREATINE, CREATININE AND PROLINE </div> </NOBR></tD> </tR> <tR> <tD VALIGN=CENTER HEIGHT= 197 ><NOBR><div> <IMG SRC="1bb113910.gif" border=0 width="275" height="145" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></div> </NOBR></tD> <tD VALIGN=TOP><NOBR><div> EACH CORD, HAS A THICK, OUTER</div> <div> PROTECTIVE PROTEIN COATING,</div> <div> SURROUNDING,THE INTERTWINED,</div> <div> THREADS OF MOLECULES, OF DNA.</div> <div> THAT CONTAIN, OUR<B> </B><A HREF="glossary_gene.htm" TARGET="_top" TITLE="TO THE GLOSSARY"><U><B>GENES</B></U></A><B>.</B></div> <bR> <div> THE COATING, IS 35 TIMES WIDER, </div> <div> THAN THE WIDTH, OF THE PAIRED, </div> <div> TWISTED THREADS, OF DNA </div> <div> MOLECULES, AT THE CENTER.</div> </NOBR></tD> </tR> <tR> <tD VALIGN=CENTER COLSPAN=2 HEIGHT= 143 ><NOBR><div> WHEN A CELL, IS FULLY GROWN AND IS TOLD TO DIVIDE, INTO 2 CELLS,</div> <div> IT BEGINS, TO FORM, THE LONG COILED CORDS, THAT YOU SEE ABOVE, THAT CONTAIN, </div> <div> TWO LONG, ENTWINED CORDS OF PAIRED DNA MOLECULES, AT THEIR VERY CENTER.</div> <div> VERY OFTEN, THE TWO DNA MOLECULES, ARE CALLED, <FONT SIZE="1" COLOR="#0000FF" FACE="Arial" >DOUBLE HELIX </FONT>MOLECULES.</div> <div> WHY ARE THEY CALLED....DOUBLE....HELIX MOLECULES ?</div> <div> WE KNOW ALREADY, THAT A HELIX,  IS A SPIRALING, COILED UP FORM, LIKE A COIL SPRING.</div> </NOBR></tD> </tR> <tR> <tD VALIGN=CENTER BGCOLOR=#FFCC66 HEIGHT= 257 ><NOBR><div> <IMG SRC="1bb223ef0.gif" border=0 width="291" height="239" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></div> </NOBR></tD> <tD VALIGN=CENTER><NOBR><div> THEREFORE,</div> <div> YOU CAN UNDERSTAND,THAT,</div> <div> A DOUBLE HELIX, IS SIMPLY,</div> <div> TWO LONG COILS, </div> <div> ONE NEXT TO THE OTHER,</div> <div> JUST AS YOU SEE,</div> <div> IN THE DRAWING, LEFT,</div> <div> THAT SHOWS A</div> <div> <B>GREEN CORD,</B></div> <div> COILED AROUND </div> <div> THE  BLUE CYLINDER AND A ,</div> <div> <B>RED</B><FONT SIZE="1" COLOR="#993366" FACE="Arial" > </FONT><B>CORD, </B><FONT SIZE="1" COLOR="#993366" FACE="Arial" >COILED</FONT></div> <div> NEXT TO THE GREEN CORD.</div> </NOBR></tD> </tR> <tR> <tD VALIGN=CENTER COLSPAN=2 HEIGHT= 138 ><NOBR><div> NOW, YOU KNOW....THE DNA DOUBLE HELIX, IS SIMPLY...</div> <div> THE TWO LONG, COILED, MOLECULES OF DNA,</div> <div> AT THE CENTER,OF OUR COILED UP, CHROMOSOMES<FONT SIZE="1" COLOR="#000000" FACE="Arial" >.</FONT></div> <bR> <bR> <div> NOW,  IF YOU WANT TO KNOW WHY, IT IS CALLED DNA<A HREF="what_is_dna.htm" TARGET="_top" TITLE="WHAT IS DNA ?"><U>...CLICK ON PAGE 3</U></A></div> <bR> </NOBR></tD> </tR> </TABLE></div> <bR> <div> <TABLE BORDER="0" CELLPADDING="2" CELLSPACING="1" WIDTH="543" BORDERCOLORLIGHT="#C0C0C0" BORDERCOLORDARK="#808080" FRAME="BOX" RULES="ALL" ALIGN="BOTTOM" HSPACE="0" VSPACE="0" > <tR> <tD VALIGN=TOP HEIGHT= 15 WIDTH="537"><IMG BORDER="0" SRC="1x1.gif" HEIGHT="15" ALIGN="bottom" WIDTH="537" HSPACE="0" VSPACE="0"></tD> </tR> </TABLE></div> <bR> <bR> <bR> <bR> <bR> <bR> <bR> </td> </tr></table></body>