1. Step One: Transcription
DNA unzips
Bases pair up: Free nucleotides in the cell find their complementary bases along the new strands. What will be different??
New backbone formed: What will be different??

2. Step One: Transcription
Watch this simplified animation:
Transcription Animation

3. TACGCATGACTAGCAAGTCTAACT
Step One: Transcription
Try it! What RNA strand will be made from the following DNA sequence?
TACGCATGACTAGCAAGTCTAACT
AUGCGUACUGAUCGUUCAGAUUGA

4. TACGCATGACTAGCAAGTCTAACT AUGCGUACUGAUCGUUCAGAUUGA
Step One: Transcription
Try it! What RNA strand will be made from the following DNA sequence?
TACGCATGACTAGCAAGTCTAACT
AUGCGUACUGAUCGUUCAGAUUGA

5. Step 1½: RNA Editing
An mRNA molecule has to be “edited” because there’s a lot of unnecessary information that needs to be removed.
An mRNA sequence that does NOT code for protein is called an intron.
A sequence that is useful in making a protein is called an exon.

6. Step 1½: RNA Editing DNA pre-RNA (in nucleus) RNA (in cytoplasm)
transcription
exon 1
interon
exon 2
exon 3
pre-RNA (in nucleus)
interon
RNA editing
exon 1
exon 2
exon 3
RNA (in cytoplasm)

7. AUG|CGU|ACU|GAU|CGU|UCA|GAU|UGA
Step Two: Translation
So how do you exactly go about determining what protein your cells are going to make?
FIRST, Divide the mRNA sequence into codons.
Codons are three-base sections of mRNA:
AUG|CGU|ACU|GAU|CGU|UCA|GAU|UGA

8. 3. Translation Three parts: 1. initiation: start codon (AUG)
2. elongation:
3. termination: stop codon (UAG)

9. Step Two: Translation Watch this simplified animation:
Translation Animation

10. Step Two: Translation Problem: There are 20 different amino acids.
There are 4 RNA bases. A T C G
phe
ile
val
pro
ala
his
asn
asp
cys
arg
leu
met
ser
thr
tyr
gln
lys
glu
trp
gly

11. Step Two: Translation
You need to figure out what amino acid matches up with each codon: ?
AUG|CGU|ACU|GAU|CGU|UCA|GAU|UGA

12. tRNA
A go-getter.
Gets the right amino acids to make the right protein according to mRNA instructions
It contains anti-codons
EX: UAC – mRNA
AUG – tRNA

13. Transfer RNA (tRNA) methionine amino acid attachment site amino acidU A C
anticodon
methionine
amino acid

14. Step Two: Translation
Since each 3-letter combination “codes” for an amino acid, you need to figure out what amino acid matches up with each codon:
AUG|CGU|ACU|GAU|CGU|UCA|GAU|UGA ?
met

15. The Genetic Code

16. Step Two: Translation
Since each 3-letter combination “codes” for an amino acid, you need to figure out what amino acid matches up with each codon:
AUG|CGU|ACU|GAU|CGU|UCA|GAU|UGA
met
arg
thr
asp
arg
ser
asp
???

17. Step Two: Translation
Since each 3-letter combination “codes” for an amino acid, you need to figure out what amino acid matches up with each codon:
AUG|CGU|ACU|GAU|CGU|UCA|GAU|UGA
met
met
thr
asp
arg
ser
asp
STOP

18. RECAP: DNA is transcribed into mRNA in the nucleus.
The mRNA leaves the nucleus and enters the cytoplasm.
The protein is translated from the mRNA sequence using tRNA and amino acids.