1. DNA Part 1: DNA Structure and Replication

2. DNA Structure- Nucleotides
3 parts:
Phosphoric acid (phosphate)
Pentose sugar (deoxyribose)
Nitrogen Base
i) Adenine & Thymine
ii) Guanine & Cytosine
Complimentary base pairs

3. DNA Structure Phosphate- sugar backbone
2 strands twisted into double helix
Hydrogen bonding between bases
Large sections of DNA make up genes
Genes determine which proteins are made in the body

4. Replication of DNA Purpose of replication:
Copying 1 DNA helix into 2 DNA helices
Cell division- Needed for growth/ repair
Each cell needs exact copy
Semi-conservative: one old strand and one new strand

5. Replication of DNA Process of replication:
Enzyme DNA Helicase unwinds/ unzips Helix
New complimentary DNA nucleotides bond (positioned & joined by DNA Polymerase)
DNA Ligase seals any breaks in backbone

6. Summary What you need to know: 3 parts of a nucleotide
4 types of complimentary bases
Steps in DNA Replication- 3 enzymes