1. Transcription

2. The Central Dogma
DNA
Transcription
RNA
Translation
Proteins

3. GOAL Use DNA to make a Protein Where does this happen?
Step 1: Replicate DNA
Step 2: Transcribe DNA into RNA
Step 3: Translate RNA into a protein
Where does this happen?
Step 1: Nucleus
Step 2: Nucleus
Step 3: Cytoplasm
Ribosomes
replication
transcription
translation

4. RNA vs. DNA DNA RNA Sugar: Deoxyribose Bases: A,T,C,G Double Stranded
Sugar: Ribose
Bases: A,U,C,G
Single Stranded

5. RNA Stands for: Ribonucleic Acid Three Types: mRNA
Carries the message from the DNA to the ribosome
tRNA
Brings amino acids from the cytoplasm to the ribosome
rRNA
Makes up part of the ribosome

6. Transcription Basics Process of taking DNA and turning it into RNA
Uses enzymes: Chemical Reaction
Happens in the nucleus

7. Transcription Starts because of an enzyme called RNA polymerase
This enzyme starts to unwind the DNA at the start of a gene
Nucleotides pair with ONE strand of DNA
RNA Polymerase (enzyme) bonds them together
start site
nucleotides
RNA Polymerase
DNA molecule

8. Transcription DNA winds back up mRNA detaches and leaves the nucleus

9. Transcription vs Replication Similarities
Both involve enzymes
Both pair the matching bases together
Happens in the nucleus

10. Transcription vs Replication Differences
Only copies ONE gene
Only copies ONE side
A will match with U instead of T
Final Product: mRNA
Replication
Copies the ENTIRE strand
Copies BOTH sides
A will match with T
Final Product: Same thing you started with (DNA)

11. Translation

12. Goal of Translation
Convert mRNA into amino acids that will end up building a protein
Proteins are polymers of amino acids

13. Amino acids are coded by mRNA base sequences.
Codons are three letters words
There are 64 different codons
Each word means (translates) into ONE of the AMINO ACIDS
codon for
methionine (Met)
leucine (Leu)

14. Codons Review: Codon=3 nucleotides that are read together.
If this is the strand of mRNA:
UCGCACGGU
The codons are:
UCG-CAC-GGU
How many codons are there? 3

15. The genetic code matches each codon to its amino acid or function.
There are 20 Amino Acids

16. Amino acids are linked to become a protein
An anticodon is a set of three nucleotides that is complementary to an mRNA codon.
An anticodon is carried by a tRNA.

17. Your Turn Strand of mRNA: AUGCGUACCUUAUAA What are the codons?
What are the anticodons?
UAC-GCA-UGG-AAU-AUU

18. tRNA carries amino acid to ribosome
ribosome forms bonds between the amino acids.

19. Important Notes Start: ALWAYS start with codon AUG
What amino acid will you always start with?
Methionine (AUG)
End: ALWAYS end with a STOP
Which codons will that be?
UAA, UAG, UGA