DNA is usually a double-helix and has two strands running in opposite directions. Each chain is made of subunits called nucleotides. Each strand has a backbone made up of deoxy-ribose sugar molecules (5 sugars) linked together by phosphate groups. Each sugar molecule is covalently linked to one of four possible bases, Adenine, Guanine, Cytosine and Thymine. A and G are larger molecules (called purines) and C and T are smaller molecules (called pyrimidines). In the DNA, …showed first 75 words of 284 total…

…showed last 75 words of 284 total…C). Two strands of DNA are obtained from one, having produced two daughter molecules which are identical to one another and to the parent molecule. BIBLIOGRAPHY http://www.pbs.org/wgbh/aso/databank/entries/do53dn.html http://www.accessexcellence.org/AB/BC/Rosalind_Franklin.html http://www.pbs.org/wgbh/aso/databank/entries/bofran.html http://www.pbs.org/wgbh/aso/databank/entries/bofran.html http://www.accessexcellence.org/AB/GG/dna_replicating.html