1. Chapter 12
DNA & RNA

2. Question of the day What does DNA stand for? Deoxyribonucleic Acid
What does it do?

3. Ch. 12 Essential Questions
What is DNA made of?
How is DNA stored?
How do DNA & RNA replicate?
What are gene mutations?

4. 12-1 DNA Evolution of DNA research
First “discovered” by Watson & Crick who beat out teams of others - first to see double helix

5. Structure of DNA Made of long units called what? NUCLEOTIDES
Each strand has 3 parts:
5 Carbon sugar - deoxyribose
1 Phosphate Group
1 Nitrogen Base

6. Parts of DNA Purine Group Pyrimidine Group
4 kinds of Nitrogen Bases in 2 groups
Purine Group
Adenine
Guanine
Pyrimidine Group
Cytosine
Thymine

7. Nitrogenous Pairs These Groups pair up 1 Purine + 1 Pyrimidine
Always with the same combo
Adenine + Thymine
Cytosine + Guanine
Or AT, CG
Connected by a Hydrogen bond
Called Base Pairing

8. Shape of DNA What does it look like? A spiral staircase
Called a double helix
2 sides of a spiral form or structure.

9. 12-2 Chromosomes & DNA
Made up of CHROMATIN - DNA & Protein packed together
Double Helices wrapped around HISTONES - proteins DNA coiled around
All packed into NUCLEOSOMES
Wrapped in COILS
Then SUPERCOILS
Makeup a Chromosome

10. DNA Replication How does DNA reproduce itself?
Double Helix “Unzips” into 2 single helices
By using an enzyme
Helicase
Put back together
Called DNA POLYMERASE
Then it “Copies” or
REPLICATES
Put back together by a fork

11. 12-3 RNA & Protein Synthesis
What is RNA?
A Genetic Message for something to be produced
RNA is a little different than DNA:
Sugar is Ribose
RNA is single stranded
RNA has Uracil, not Thymine

12. Different Types of RNA Many functions of RNA but mostly makes proteins
Messenger RNA (mRNA) - Instruction Carrier for proteins
Ribosomal RNA (rRNA) - where proteins are assembled
Transfer RNA (tRNA) - moves amino acids to ribosomes (Taxi)

13. How to Make RNA Where DNA gets converted into RNA TRANSCRIPTION
Uses RNA Polymerase (RP)
Where does RP know where to start & stop?
PROMOTERS - enzyme that binds to specific DNA sequence

14. RNA Is Made - The Genetic Code
RNA makes amino groups
Groups called CODONS
Group of 3 specific nucleotides
64 possible codon combinations

15. Roles of DNA & RNA DNA is the master plan
RNA is the blueprint of master plan
DNA remains safely in nucleus
RNA goes to protein building sites in cytoplasm & ribosomes

16. 12-4 Mutations Mutation - to change Not all mutations are bad
Can have two kinds:
Gene - on a single gene
Chromosome - whole chromosome change
Point Mutation - one nucleotide is affected
Frameshift - Deletes 1 nucleotide and causes every one to shift up

17. 12-5 Gene Regulation Some Genes are turned on & off at times
Turn on/off at promoter
Use Operons & Hox genes to help develop and turn on/off parts of genes

18. Final Thoughts on Mutations
Are all mutations bad?
Do they need to cause immediate change?
Can there be real life X-Men?