1. Agenda 3/7 Protein Warm Up Transcription Notes Transcription Model
Homework:
1. Chp 17 reading and notes (due Friday)
2. Transcription Video and Notes
3. Cell Differentiation Video and Notes

2. Protein Warm UP
Name 10 proteins we have learned about this year 

3. Proteins!

4. A gene is a sequence of DNA that can direct the synthesis of a product
Genes do not all code for a protein
They all DO code for an RNA molecule
Some of those RNA molecules will be translated into proteins
Some will serve other functions (like gene regulation)
Genes

5. Protein Synthesis Overview
1. Transcription (DNA->mRNA)
2. Translation (mRNA ->Protein)
DNA is located in the nucleus of eukaryotes
mRNA is the intermediate between the DNA code and synthesis of protein

6. RNA vs. DNA DNA RNA Double stranded Deoxyribose sugar
Thymine (T) instead of Uracil (U)
Restricted to Nucleus
One use-used as template for RNA synthesis
RNA
Single stranded
Ribose sugar
U instead of T
Can enter and leave nucleus
Multiple Uses
RNA vs. DNA

7. Types of RNA

8. Prokaryotes vs. Eukaryotes
No nucleus so transcription and translation happen simultaneously
No RNA processing
No introns (regions of non coding RNA that get cut out)
Eukaryotes
Nucleus for transcription
RNA processing and introns

9. Transcription: RNA synthesis from DNA template
1. Initiation
2. Elongation
3. Termination
(4?) RNA Processing

10. Initiation Promoter region: region of DNA prior to the start of a gene
Promoter region decided which side of DNA will be transcribes
Prokaryotes: RNA polymerase attaches directly to the promoter region
Eukaryotes: Proteins called transcription factors help RNA polymerase attach to promoter region

11. Elongation
RNA Polymerase unwinds DNA and pairs RNA nucleotide to template strand of DNA
RNA is made 5’3’, so the DNA gene is going in the 3’5’ direction
RNA polymerase can do 60 nucleotides/minute

12. Termination
RNA synthesis will keep going until RNA Polymerase encounters a sequence of DNA that causes it to ‘fall off’ the DNA template strand and end transcription
Multiple ways in Prokaryotes
1. Hairpin loop- lots of G-C bonds that form a loop and causes stress on RNA polymerase
2. Rho dependent- a protein that destabilizes the interaction between RNA polymerase and DNA template

13. Termination

14. Termination in Eukaryotes
Termination factor proteins block further transcription when they bind to a termination sequence in DNA or mRNA
Some will actually cleave mRNA so transcription stops
Not as much known as prokaryotic termination

15. RNA Processing
In eukaryotes, the RNA is processed further after transcription termination occurs
1. 5’ cap is added (modified guanine nucleotide added)
2. Poly-A-tail ( adenine nucleotides added at 3’ end)
3. Introns are removed

16. Intron Removal Splicesomes are made of snRNPs (proteins and snRNA)
They splice the intron at a specific sequence of RNA

17. Alternative Splicing
Different exons (not an intron) are recombined in different ways for certain mRNA
This increases the number of different proteins that can result from a gene

18. Next up…translation The mRNA has been synthesis and processed
Now referred to as ‘mature mRNA’
Ready to go to the cytoplasm for translation

19. Transcription Posters
Create a template strand of DNA (must show shapes of sugar, phosphates, and nitrogenous bases)
Create an mRNA strand that matches (show correct base pairing)
USE CONSTRUCTION PAPER CUT OUTS FOR THIS PART 
Depict RNA polymerase creating new mRNA strand
Show the promoter region of DNA
Show all three steps of transcription (drawn and explained)
Show RNA processing occurring
Incorporate all the key words from class
*My advice: make ‘half’ of a poster so we can show translation in the other half (today will be in nucleus)