Packet 6, Part 1-DNA: The Molecule of Heredity
DNA
•
Deoxyribonucleic Acid
 “instructions for ____________________” for all cells
 In _______________________ of eukaryotes; in _____________________________ of prokaryotes
 Controls the cell
• By producing __________________________________
Structure of DNA
•
DNA is a nucleic acid made of ________________________________ subunits
Each nucleotide contains 3 parts
1. ________________________________________- a simple sugar
2. ___________________________ group
3. Nitrogen __________________-4 different types
4 Nitrogen BasesDouble ringed bases
1. ______________________ (A)
2. ______________________ (G)
Single ringed bases
3. ______________________ (T)
4. ______________________ (C)
Each nucleotide contains:
1 __________________
1 deoxyribose ______________
1 of the 4 nitrogen ____________________
 ___________________________ are linked together to form DNA
Discovery of DNA Structure
 In the 1940’s- scientists knew :
 DNA was the molecule of _______________
 DNA was a_________________________ acid
 DNA was made of _______ nucleotides
__________________, ___________________, ________________, ________________
 In any cell the amounts of
_________________ always = _______________ and
_________________ always = _______________
 1950’s: Rosalind _______________________studied DNA using a technique called x-ray diffraction.
 Added information on the ________________ of the molecule
What they didn’t know was how it all fit together in the __________________________ structure of DNA !
 1953 ____________________ and _______________________ discovered DNA is a double helix
DNA Double Helix:
 _____ strands of DNA in a _________________ _____________________
 Sugar and phosphate alternate the ________________________ of the ladder
 Nitrogen base pairs are the ____________________ of the ladder according to the base pairing rule
Base Pairing Rule
________ pairs with _______ with _______ Hydrogen bonds
________ pairs with _______ with _______ Hydrogen bonds
Practice Base Pairing Rule
A
C
T
G
G
A
T
C
A
G
T
C
I
I
I
I
I
I
I
I
I
I
I
I
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