1. Characteristics of DNA

2. DNA Composition 4 different nukleotides (A, T, C, G)
Each nucleotide comprises of a phosphate, a sugar, and a base
The sugar molecule in the DNA is deoxyribose (Ribose in RNA)
Uracil is replaced with thymine in RNA

3. DNA Composition A & G purines C & T pirimidines
[purines] = [pirimidines]
[A] = [T] ; [C] = [G]
A/T base pairs contains 2 hydrogen bonds
C/G base pairs contains 3 hydrogen bonds

4. Structure of DNA Double-stranded helicoidal structure
Strands are in opposite direction and antiparallel to each other
Complementary strands are bounded with hydrogen bonds to each other
Strands have complementary sequences

5. Structure of an Nucleotide Adenosine Mono Phosphate (AMP)OH HO
Phosphate
NH2 N
Base - H+ OH O
CH2
Sugar H 2’ 3’ 4’ 5’ 1’
Nukleotide
Nukleoside OH

6. Purines Pirimidines Uracil CH3 N O NH Thymine N Adenine NH2 NH2 O N NH
(RNA)
CH3 N O NH
Thymine
(DNA) N
Adenine
NH2
NH2 O N NH
Guanine N O
NH2
Cytosine

7. Base Pairs Guanine and CytosineH O N
Guanine - N O H
Cytosine + + - - +

8. Base Pairs Adenine and Thymine- +
Adenine
CH3 N O H + -
Thymine

9. Base Pairs Adenine and CytosineH
Cytosine - + N H - +
Adenine

10. Base Pairs Guanine and Tyhmine
CH3 N O H + -
Tyhmine H O N
Guanine + -