1. DNA
Chapter 12.1/12.2

2. DNA = deoxyribose nucleic acid
What is DNA?
DNA = deoxyribose nucleic acid

3. What is DNA? DNA is made up of nucleotides. Nucleotides:
5 – carbon sugar (deoxyribose)
Phosphate group
Nitrogenous base
Adenine – Guanine
Thymine – Cytosine

4. Double Helix
DNA is a double helix.
 Twisted ladder

5. Base Pairings Adenine – Guanine Thymine – Cytosine
They’re held together by hydrogen bonds
Hydrogen bonds are WEAK
Why would having weak bonds be good for DNA?
These are base pairings!

6. DNA and Chromosomes
What does DNA look like in prokaryotic cells? What does DNA look in eukaryotic cells?

7. Chromosomes vs. Chromatin
DNA wrapped around a protein
Found in the nucleus
Chromosomes:
DNA coiled tightly
Shaped liked an “X”
Found in the nucleus

8. THINK!
What does replicate mean? Does DNA replicate?? If it does, why is that important??

9. DNA Replication DNA separates into two strands Replication fork
DNA “unzips” when it separates

10. DNA Replication After DNA separates, new base pairs are added. AGGTCTA
What would the new base pairs be??

11. How DNA Replicates
DNA polymerase = the enzyme in charge of adding new bases to unzipped DNA.

12. PRACTICE GTACC AGGTC GCCGATA TTAATTAAGGC GTGTATAAA GATTACA
GATGATCCGTCGCTCGC
AGGAAGGTGATAGGC