1. DNA Structure and Replication
GATACA
CTATGT

2. DNA structure Nucleic acid Three parts Sugar is deoxyribose
Nucleotides
Three parts
Nitrogenous base
5-carbon sugar
Phosphate group
Sugar is deoxyribose
Bases are adenine, cytosine, quanine, thymine

3. Chargaff’s Rule Amount of nucleic acid was different in most organisms
Amounts of the nucleotides were different in most organisms.
Amount of A equaled the amount of T
Amount of G equaled the amount of C

4. Franklin
X ray diffraction pictures of DNA (look at page 346 to see the picture)

5. Watson and Crick
Solved the structure of DNA problem by building models
Used evidence from Franklin and Chargaff
Base pairing was done by hydrogen bonding
Structure is called a double helix
Suggested how the strands could replicate

6. Replication DNA is copied in the S phase of the cell cycle
Enzymes separate the two strands
Enzymes synthesize new strands that base pair with the original strands

7. Chromatin DNA and protein make up the chromosomes
Protein is called histone
Histones form particles called nucleosomes that help fold and package DNA so that it fits into the nucleus (remember the chromosome is in the nucleus).