1. Transcription & Translation
Protein Synthesis
Biology 12

2. Central Dogma In nucleus Produced in nucleus Travels to cytoplasm
Produced in cytoplasm

3. Task Complete the following table: Transcription Translation Location
Template
(What is read)
Purpose
Outcome (End result)

4. Definition: Transcription
Nucleus
Location
DNA
Template
(What is read)
To change DNA into a form that can make a protein
Purpose
Messenger RNA
(mRNA)
Outcome
(End result)

5. Definition: Translation
Location
Cytoplasm (by ribosome)
Template
(What is read)
mRNA
Purpose
Amino acids assembled in particular order to make a protein
Outcome
(End result)
Protein (polypeptide)

6. Central Dogma

7. Task Transcription & Translation Using pages 239/240
Make notes for EACH about:
Initiation (how it starts)
Elongation (how it is built)
Termination (how it ends)

8. Transcription ‘to copy’
Initiation:
RNA polymerase binds to ‘promoter’
Elongation:
RNA polymerase builds mRNA
From DNA 3’ end
Uses complimentary base pairing
Remember: thymine (T) is replaced by uracil (U)

9. Transcription ‘to copy’
Termination:
RNA polymerase reaches end of gene
Stops transcribing
End Result:
mRNA breaks away from DNA
mRNA exits nucleus

10. Translation ‘new language’
Initiation:
Ribosome binds to start codon
Elongation:
Ribosome moves along mRNA
From mRNA 5’ end
3 nucleotides = codon = amino acid
tRNA delivers proper amino acid
Turn to page 240!

11. Translation ‘new language’
Termination:
Ribosome reaches stop codon
Stops translating
End Result:
Ribosome falls off mRNA
Protein (polypeptide chain) is released

12. Start and Stop Codons Page 240! Start Codon: Begins translation
AUG (universal start codon)
ALSO Codes for methionine (Met)
Sometimes GUG or UUG
Stop Codon:
Ends translation
UGA, UAA, UAG
Page 240!

13. Transfer RNA (tRNA) Delivers amino acid to ribosome Reads mRNA codon
Has a matching ‘anticodon’
One tRNA for each amino acid

14. The Whole Picture Next amino acid to be added to polypeptide Growing
tRNA
mRNA

15. Figure (pg 239)

16. Example DNA template: 3’ TAC ACA CGG AAT GGG TAA AAA ACT 5’
Complimentary DNA
Read from DNA template (start reading at 3’)
mRNA codon
tRNA anticodon
Read from mRNA
Amino Acids (protein)

18. United Nations Conference
Who’s who?
Mr. Na
mRNA
Meri Boso
ribosome
Flash cards
tRNA
Translation
protein

19. Task # 2, 4 – 6, 9 – 11 Omit “ribosomes” for #4 # 2 # 3, 4 & 6
(page 241)
Omit “ribosomes” for #4
# 2
(page 249)
# 3, 4 & 6
(page 254)
DNA rules!

20. Task A: #2 – Central Dogma
DNA makes RNA (mRNA)
through transcription
RNA makes proteins
through translation

21. #4 – RNA types mRNA tRNA rRNA Messenger RNA
End product of transcription
Takes message from DNA into cytoplasm
Used by ribosome to make protein
tRNA
Transfer RNA
Delivers amino acid to ribosome
rRNA
Ribosomal RNA
Helps form and maintain ribosomes

22. #5 – DNA vs. RNA DNA Sugar – deoxyribose Double stranded
Base pair – thymine
Stays in nucleus
Can replicate itself
Longer strands
RNA
Sugar – ribose
Single Stranded
Base pair – uracil
Can leave nucleus
Cannot replicate itself
Shorter strands

23. #6 – Transcription/Translation
Purpose:
To make mRNA from DNA
Location:
Nucleus
Translation
Purpose:
To make a specific protein from mRNA
Location:
Cytoplasm (ribosome)

24. #9 – Stop vs. Start Codon Start Codon mRNA code
Tells ribosome to begin translation
Example:
AUG
Also codes for methionine
And: UUG, GUG
Stop Codon
mRNA code
Stops translation of that specific amino acid chain
Examples:
UAA, UAG, UGA

25. #10 – Transcribe to mRNA DNA: GGA TCA GGT CCA GGC AAT
TTA GCA TGC CCC AA
*mRNA*:
CCU AGU CCA GGU CCG UUA
AAU CGU ACG GGG UU

26. #11 – Translate to Amino Acids
mRNA sequence divided into codons:
GGC AUG GGA CAU UAU UUU GCC CGU UGU GGU GGG GCG UGA
*Protein translation*:
Gly Met(start) Gly His Tyr Phe Ala
Arg Cys Gly Gly Ala (stop)

27. Task B: #2 – Transcribe to mRNA
DNA:
TAC TAC GGT AGG TAT A
*mRNA*:
AUG AUG CCA UCC AUA U

28. Task C: #3 – Anticodons

29. #4 – Change in 3rd Base May Not Result in Error
Why not?
Amino acids have more than one codon
Example: proline
Codons CCU, CCC, CCA, and CCG
CC - always codes for proline
Third base/nucleotide does not matter

30. #6 – Translate to Amino Acids
mRNA:
GGC CCA UAG AUG CCA CCG GGA AAA GAC UGA GCC CCG
*Protein translation*:
Met (start) Pro Pro Gly Lys Asp (stop)