Protein synthesis involves two main steps: transcription and translation. In transcription, RNA polymerase uses DNA as a template to make mRNA strands in the nucleus. The mRNA then moves to the cytoplasm. In translation, ribosomes read the mRNA and join amino acids specified by codons through attachment to tRNAs. The amino acids bond together into a protein chain that eventually folds into its functional tertiary structure.

1. Protein Synthesis
By: Amanda Moore

2. Nucleus
Ribosomes
Cytoplasm

3. Nucleus
Ribosomes
Cytoplasm

4. Nucleus
Ribosomes
Cytoplasm

5. T
T
A
G
A
T
T
C
G
A
T
G
C
A
T
A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
RNA Polymerase
mRNA

6. T
T
Nucleus
A
G
A
T
T
C
G
A
T
G
C
A
A T
A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
RNA Polymerase
mRNA
Ribosomes

7. T
T
Nucleus
A
G
A
T
T
C
G
A
T
G
C
U A
A T
A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
RNA Polymerase
mRNA
Ribosomes

8. T
T
Nucleus
A
G
A
T
T
C
G
A
T
G
G C
U A
A T
A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
RNA Polymerase
mRNA
Ribosomes

9. C
G
U
A
T
T
Nucleus
A
G
A
T
T
C
G
A
T
G
C
A
T
A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
RNA Polymerase
mRNA
Ribosomes

10. A
C
G
U
A
T
T
Nucleus
A
G
A
T
T
C
G
A
T
G
C
A
T
A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
RNA Polymerase
mRNA
Ribosomes

11. U
A
C
G
U
A
T
T
Nucleus
A
G
A
T
T
C
G
A
T
G
C
A
T
A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
RNA Polymerase
mRNA
Ribosomes

12. C
U
A
C
G
U
A
T
T
Nucleus
A
G
A
T
T
C
G
A
T
G
C
A
T
A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
RNA Polymerase
mRNA
Ribosomes

13. G
C
U
A
C
G
U
A
T
T
Nucleus
A
G
A
T
T
C
G
A
T
G
C
A
T
A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
RNA Polymerase
mRNA
Ribosomes

14. A
G
C
U
A
C
G
U
A
T
T
Nucleus
A
G
A
T
T
C
G
A
T
G
C
A
T
A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
RNA Polymerase
mRNA
Ribosomes

15. A
A
G
C
U
A
C
G
U
A
T
T
Nucleus
A
G
A
T
T
C
G
A
T
G
C
A
T
A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
RNA Polymerase
mRNA
Ribosomes

16. U
A
A
G
C
U
A
C
G
U
A
T
T
Nucleus
A
G
A
T
T
C
G
A
T
G
C
A
T
A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
RNA Polymerase
mRNA
Ribosomes

17. C
U
A
A
G
C
U
A
C
G
U
A
T
T
Nucleus
A
G
A
T
T
C
G
A
T
G
C
A
T
A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
RNA Polymerase
mRNA
Ribosomes

18. U
C
U
A
A
G
C
U
A
C
G
U
A
T
T
Nucleus
A
G
A
T
T
C
G
A
T
G
C
A
T
A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
RNA Polymerase
mRNA
Ribosomes

19. A
U
C
U
A
A
G
C
U
A
C
G
U
A
T
T
Nucleus
A
G
A
T
T
C
G
A
T
G
C
A
T
A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
RNA Polymerase
mRNA
Ribosomes

20. A
A
U
C
U
A
A
G
C
U
A
C
G
U
A
T
T
Nucleus
A
G
A
T
T
C
G
A
T
G
C
A
T
A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
RNA Polymerase
mRNA
Ribosomes

21. T
T
Nucleus
A
G
A
T
T
C
G
A
T
G
C
A
T
A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
AUGCAUCGAAU
Ribosomes
Nuclear por

22. T
T
Nucleus
A
G
A
T
T
C
G
A
T
G
C
A
T
A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
Cytoplasm
Ribosomes
AUGCAUCGAAU

23. A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
Cytoplasm
Ribosomes
Nucleus
AUG CAU CGA AUC UAA
Codon
Starting
codon
Codon
Codon
Stopping
codon

24. A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
Cytoplasm
Ribosomes
Nucleus
Ribosome
Small
subunit
Large
subunit
AUG CAU CGA AUC UAA
Codon
Starting
codon
Codon
Codon
Stopp
codon

25. A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
Cytoplasm
Ribosomes
Amino acid
Nucleus
Anti
codon
tRNA
UAC
Ribosome
Small
subunit
Large
subunit
AUG CAU CGA AUC UAA
Codon
Starting
codon
Codon
Codon
Stoppi
codon

26. A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
Cytoplasm
Ribosomes
Amino acid
Anti
Nucleus codon
tRNA
UAC
Amino acid
tRNA
GUA
Ribosome
Small
subunit
Large
subunit
AUG CAU CGA AUC UAA
Codon
Starting
codon
Codon
Codon
Stopping
codon

27. A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
Cytoplasm
Ribosomes
Amino acid
Amino acid
Peptide
Bond
Nucleus
Anti
codon
tRNA
tRNA
GUA
UAC
Codon
Codon
Ribosome
Small
subunit
Large
subunit
AUG CAU CGA AUC UAA
Starting
codon
Codon
Stopping
codon

28. A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
Cytoplasm
Ribosomes
Amino acid
Peptide
Bond
Peptide
Bond
tRNA
Anti
codon
Nucleus
Amino acid
UAC
tRNA
UAG
Ribosome
Small
subunit
Large
subunit
AUG CAU CGA AUC UAA
Codon
Starting
codon
Codon
Codon
Stopp
codo

29. A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
Cytoplasm
Ribosomes
Amino acid
Peptide
Bond
Peptide
Bond
Peptide
Bond
tRNA
Nucleus
UAG
Ribosome
Small
subunit
Large
subunit
AUG CAU CGA AUC UAA
Codon
Starting
codon
Codon
Codon
Stopp
codon

30. A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
Cytoplasm
Ribosomes
Amino acid
Peptide
Bond
Nucleus
Ribosom
Small
subuni
Large
subuni
AUG CAU CGA AUC UA
Codon
Starting
codon
Codon
Codon
Sto
cod

31. A
A
T
C
T
A
A
G
C
T
A
C
G
T
A
Cytoplasm
Ribosomes
Amino acid
Ribosome
Small
subunit
Large
subunit
Nucleus
AUG CAU CGA AUC UA
Codon
Starting
codon
Codon
Codon
Stop
codo

32. Protein synthesis
Protein synthesis starts off with a process called
transcription. Transcription is when RNA
polymerase makes a mRNA strand using DNA. RNA
polymerase unwinds DNA at the start of a gene. It
uses one strand to get the complementary
nucleotides for the mRNA strand. On the mRNA, A
and U go together and G and C go together. The
mRNA then breaks off when RNA polymerase is
done using the DNA and goes into the cytoplasm.
The DNA then goes back together.

33. Protein synthesis cont.
• The next step of protein synthesis is translation. Translation
is when the mRNA strand is read to make amino acids. The
mRNA comes in contact with a ribosome and the ribosome
reads the three sets of nucleotides. The ribosome begins at
the start codon. Then tRNA transfer amino acids. The tRNA
has an anti-codon that is the complement to the nucleotide
on the mRNA. The tRNA binds temporarily on the mRNA
until another tRNA comes to put an amino acid on another
codon. The amino acid then forms a peptide bond with
another amino acid. The ribosome stops at the stop codon.
After all of the amino acids are made and bonded together,
they fold on themselves and form a tertiary structure to
give it a function.