1. The Structure of Deoxyribonucleic Acid
DNA
The Structure of Deoxyribonucleic Acid

2. Cell division and DNA replication
Cells divide
Growth, Repair, Replacement
Before cells divide they have to double cell
structures, organelles, and their genetic
information

3. How does DNA make more DNA?
DNA replication
How does DNA make more DNA?

4. DNA Structure - Discovery
Structure was discovered in 1953 by James
Watson and Francis Crick

5. DNA
DNA = Deoxyribose nucleic acid
Made out of sugars (deoxyribose), phosphates
and nitrogen bases

6. Rungs formed by nucleotide bases
DNA structure
“Backbone” formed by
sugar-phosphate
Rungs formed by nucleotide bases

8. Bases always bond with the same partner:
purine - pyramidine
Adenine – Thymine Guanine - Cytosine

9. Each DNA strand serves as a template for the assembly of a new strand
DNA replication
Each DNA strand serves as a template for the assembly of a new strand

10. 2 daughter DNA molecules
DNA replication: Summary
Result:
2 daughter DNA molecules
Each containing 1 parent strand and 1 new strand
Identical to each other
Identical to parent DNA