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The Structure of DNA. The molecule of life. DNA is a Molecule. Held together with covalent bonds ** Hydrogen Bonds** hold the bases together (Adenine, Guanine, Cytosine, Thymine). http://www.envirohealthtech.com/images/DNA.jpg. The Double Helix.
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The Structure of DNA The molecule of life
DNA is a Molecule • Held together with covalent bonds • ** Hydrogen Bonds** hold the bases together (Adenine, Guanine, Cytosine, Thymine) http://www.envirohealthtech.com/images/DNA.jpg
The Double Helix http://eur.news1.yimg.com/eur.yimg.com/xp/afpji/20060513/060513030238.z1molysc0_human-dna-double-helix-b.jpg
Ladder-like Structure • The base pairs form the “rungs” • The phosphate and deoxyribose sugar form the uprights http://academy.d20.co.edu/kadets/lundberg/images/dna.gif
The Sugar Phosphate Backbone O OH P O HO O CH2 H H H H OH H http://www-math.mit.edu/~lippert/18.417/lectures/01_Intro/Pictures/10000000000001B00000023B34B57A9B.jpg
Nucleotide The basic unit of the DNA molecule Phosphate group Base (adenine, guanine, thymine, or cytosine) Deoxyribose – pentose sugar (5 carbons)
Polynucleotide • A string of nucleotides • The order of the bases determines the genetic code of the organism
DNA Replication The molecule ‘unzips’ and free nucleotides attach to their base-pair partners to form two new double helices http://courses.cm.utexas.edu/jrobertus/ch339k/overheads-2/ch10_DNA-rep.jpg
Base Pairs A - T G - C
Semi-conservative Replication New “daughter” DNA molecules are made up of one strand from the original “parental” DNA molecule and one newly formed strand. http://nobelprize.org/educational_games/medicine/dna/b/replication/replication_schem.html
The Process of Replication The chromosome unwinds (Chromosomes are tightly packed strands of DNA) http://www.microbeworld.org/news/articles/human_genes.aspx
The Process of Replication The hydrogen bonds between the base pairs are broken http://www.ba-education.demon.co.uk/gifs/replication.jpg
http://en.wikipedia.org/wiki/Double_helix The Process of Replication The two polynucleotide strands separate
The Process of Replication Free nucleotides attach to the template made by the parent strands. And Voilà!!Two identical DNA molecules. http://www.chemsoc.org/ExemplarChem/entries/2003/imperial_Burgoine/replication.jpg