DNA
Deoxyribonucleic
Acid
DNA
I.
General Information
A. Nucleic acid = acid found in nucleus
B. F(x)s
1. Carries & transmits
genetic code
2. Codes for proteins which
determine traits
E.g. blue eyes, red hair
DNA F(x)s (cont.)
3. Gene = section of DNA that
codes for a protein
4. Proteins perform almost all
of the essential life functions
of cells & organisms
5. DNA codes for what an organism
can do and be
C. History of DNA Research
1. 1949 Chargaff ’s rule
# of Adenines =
# of Thymines
# of Guanines =
# of Cytosines
C. History of DNA Research
2. 1952 Rosalind Franklin &
Maurice Wilkins X-ray pattern of DNA
C. History of DNA Research
3. 1953 Watson & Crick reveal
3-D model of DNA molecule
C. History of DNA Research
(1958- Franklin dies)
4. 1962 Watson & Crick (& Wilkins)
Nobel Prize for 3-D model of DNA
?’s 1-9
D. DNA Structure
1.
Shape =
double helix
(2 strands)
coiled ladder
D. DNA Structure
2. Building block = nucleotide
3. Nucleotide =
 Phosphate
 Sugar (deoxyribose)
 Nitrogenous Base
(A, T, C, or G)
 Hydrogen bond
between N-bases
D. DNA Structure
4. Complementary base
pairing

N-bases always pair
with same partner

Adenine with Thymine

Cytosine with Guanine
?’s 10-14
D. DNA Structure
If
we know what
one strand of
DNA molecule is,
we know the other
 What is the other side if one side is
CATTAGCAT ?
GTAATCGTA
D. DNA Structure
5. Sequence of bases is the genetic code
3D DNA Model Animation

http://www.ebi.ac.uk/2can/biology/molecules_
dna.html animation of
?’s 15-17