Section 10-1: DNA
Read pages 185-187 and fill in the information below regarding the structure of DNA
Structure of DNA
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DNA is made of repeating subunits called _____________________.
Each DNA molecule consists of ______________ long chains of nucleotides.
There are three parts to a nucleotide:
o A sugar called ___________________________
o A _____________________ group
o A nitrogen-containing _______________
 The four possible bases are _______________________,
______________________, _______________________, and
______________________.
o Draw a picture of a nucleotide in the space below.
The Double Helix
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In 1953, ____________________________ and ___________________________
suggested a model for the structure of DNA
Their model suggested that DNA was made of two chains of nucleotides wrapped
around each other forming a spiral, a shape called a _____________________________.
According to figure 10-4, X-ray photographs of DNA by
_______________________________ showed that DNA is a helix.
What 2 parts of a nucleotide for the “backbone” of DNA? ____________________ and
_______________________
Which part of the nucleotide faces the center of the helix? _______________________
_____________________ bonds hold the 2 chains together
Complementary Base Pairing
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____________________ and ___________________ form 3 hydrogen bonds.
____________________ and ___________________ form 2 hydrogen bonds.