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19 terms

12.2 The Structure of DNA

STUDY
PLAY
chemical components of DNA
DNA is a nucleic acid made up of nucleotides joined into long strands or chains by covalent bonds
nucleic acid
make up protein, long slightly acidic molecules originally identified in cell nuclei
nucleotides
building blocks of nucleic acids
nucleotides that make up DNA
each nucleotide contains a deoxyribose molecule, a phosphate group, and a nitrogen-containing base
the nitrogen containing bases
Adenine, Guanine, Cytosine, and Thymine
Nitrogenous bases
another word for the bases in DNA that contain nitrogen
How are the nucleotides in a strand of DNA joined?
covalent bonds formed between the sugar of one nucleotide and the phosphate group of the next
UV light and nitrogenous bases
the bases have a chemical structure that is exceptionally good at absorbing UV light (why we get tan)
Order & sequence of nucleotides
sequence of a strand does not matter but A always matches up with T and G always matches up with C
scientists responsible for discovering the structure of DNA
Erwin Chargaff, Rosalind Franklin, James Watson, and Francis Crick
Chargaff's Rule
the observation that A = T and G=C
What did Franklin's x-rays discover?
x-shape pattern hinted that the strand in DNA are in the double-helix shape
What did Watson and Crick discover?
worked on figuring out the structure of DNA, built 3D models, saw Franklins x-rays, breakthrough model of the double-helix in DNA
What does the double-helix model tell us about DNA?
explains Chargaff's rule of base pairing and how two strands of DNA are held together
double helix model
What does DNA stand for?
deoxyribose nucleic acid
What does it mean for DNA to be antiparallel?
runs in opposite directions
What bonds the 2 strands of DNA together
hydrogen
base pairing
the nearly perfect fit between A-T and G-C nucleotides

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