Protein synthesis involves three main steps: 1) DNA is transcribed into mRNA in the nucleus, 2) the mRNA exits the nucleus and binds to ribosomes in the cytoplasm, and 3) the mRNA is translated by ribosomes assembling amino acids into a protein chain according to the mRNA codons. The protein then folds into its final tertiary structure.

1. Protein Synthesis
By Sammy Gigliotti

2. DNA
Nucleus
Cytoplasm
Cell

3. DNA
Nucleus
Cytoplasm

4. DNA
Nucleus
Cytoplasm

5. DNA
Nucleus

6. DNA
Nucleus

7. DNA
Nucleus

8. DN
Nucleus

9. DN
Nucleus

10. Protein Synthesis takes place
inside of the DNA
DN
Nucleus

11. RNA polymerase binds on to
the DNA double helix and
adds the complementary
nucleotides.
~~~~~~~~~~~~~~~~~~~~T A C A G G C A A C A C A C T ~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~ A T G T C C G T T G T G T G A~~~~~~~~~~~~~~~~~~~~

12. A
T
RNA polymerase binds on to
the DNA double helix and
adds the complementary
nucleotides.
~~~~~~~~~~~~~~~~~~~~T A C A G G C A A C A C A C T ~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~ A T G T C C G T T G T G T G A~~~~~~~~~~~~~~~~~~~~

13. A
U
G
RNA polymerase binds on to
the DNA double helix and
adds the complementary
nucleotides.
U
~~~~~~~~~~~~~~~~~~~~T A C A G G C A A C A C A C T ~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~ A T G T C C G T T G T G T G A~~~~~~~~~~~~~~~~~~~~

14. A
U
G
U
G
RNA polymerase binds on to
the DNA double helix and
adds the complementary
nucleotides.
G
~~~~~~~~~~~~~~~~~~~~T A C A G G C A A C A C A C T ~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~ A T G T C C G T T G T G T G A~~~~~~~~~~~~~~~~~~~~

15. A
U
RNA polymerase binds on to
the DNA double helix and
adds the complementary
nucleotides.
G
U
G
G
~~~~~~~~~~~~~~~~~~~~T A C A G G C A A C A C A C T ~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~ A T G T C C G T T G T G T G A~~~~~~~~~~~~~~~~~~~~

16. U
G
U
G
G
C
A
A
RNA polymerase binds on to
the DNA double helix and
adds the complementary
nucleotides.
~~~~~~~~~~~~~~~~~~~~T A C A G G C A A C A C A C T ~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~ A T G T C C G T T G T G T G A~~~~~~~~~~~~~~~~~~~~

17. U
G
U
UG
U
G
U
RNA polymerase binds on to
the DNA double helix and
adds the complementary
nucleotides.
~~~~~~~~~~~~~~~~~~~~T A C A G G C A A C A C A C T ~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~ A T G T C C G T T G T G T G A~~~~~~~~~~~~~~~~~~~~

18. U
G
U
UG
RNA polymerase binds on to
the DNA double helix and
adds the complementary
nucleotides.
U
G
U
G
U
G
A
~~~~~~~~~~~~~~~~~~~~T A C A G G C A A C A C A C T ~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~ A T G T C C G T T G T G T G A~~~~~~~~~~~~~~~~~~~~

19. U
U
UG
U
G
U
G
U
G
A
RNA polymerase binds on to
the DNA double helix and
adds the complementary
nucleotides.
~~~~~~~~~~~~~~~~~~~~T A C A G G C A A C A C A C T ~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~ A T G T C C G T T G T G T G A~~~~~~~~~~~~~~~~~~~~

20. G
U
G
U
G
A
RNA polymerase binds on to
the DNA double helix and
adds the complementary
nucleotides.
~~~~~~~~~~~~~~~~~~~~T A C A G G C A A C A C A C T ~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~ A T G T C C G T T G T G T G A~~~~~~~~~~~~~~~~~~~~

21. G
U
G
A
RNA polymerase binds on to
the DNA double helix and
adds the complementary
nucleotides.
~~~~~~~~~~~~~~~~~~~~T A C A G G C A A C A C A C T ~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~ A T G T C C G T T G T G T G A~~~~~~~~~~~~~~~~~~~~

22. RNA polymerase binds on to
the DNA double helix and
adds the complementary
nucleotides.
~~~~~~~~~~~~~~~~~~~~T A C A G G C A A C A C A C T ~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~ A T G T C C G T T G T G T G A~~~~~~~~~~~~~~~~~~~~

23. mRNA strand leaving the
nucleus.
DNA
Nucleus
Cytoplasm
Cell
Nuclear pore

24. mRNA strand leaving the
nucleus.
DNA
Nucleus
Cytoplasm
Cell
Nuclear pore

25. mRNA strand leaving the
nucleus.
DNA
Nucleus
Cytoplasm
Cell
Nuclear pore

26. mRNA strand leaving the
nucleus.
DNA
Nucleus
Cytoplasm
Cell
Nuclear pore

27. mRNA strand leaving the
nucleus.
DNA
Nucleus
Cytoplasm
Cell
Nuclear pore

28. mRNA strand enters the
cytoplasm and heads
towards the ribosomes
DNA
Nucleus
Nuclear pore
Cytoplasm
Ribosomes
Cell

29. mRNA strand enters the
cytoplasm and heads
towards the ribosomes
DNA
Nucleus
Nuclear pore
Cytoplasm
Ribosomes
Cell

30. mRNA strand enters the
cytoplasm and heads
towards the ribosomes
DNA
Nucleus
Nuclear pore
Cytoplasm
Ribosomes
Cell

31. Large and small
subunits of a
ribosome binding
with mRNA
Large Subunit
Ribosome
A U G
G U U
U A A
A G C
U A A

32. Large and small
subunits of a
ribosome binding
with mRNA
Large Subunit
Ribosome
A U G
G U U
U A A
A G C
U A A

33. Large and small
subunits of a
ribosome binding
with mRNA
Large Subunit
Ribosome
A U G
G U U
U A A
A G C
U A A

34. Large and small
subunits of a
ribosome binding
with mRNA
Large Subunit
Ribosome
A U G
G U U
U A A
A G C
U A A

35. Large and small
subunits of a
ribosome binding
with mRNA
Large Subunit
Ribosome
A U G
G U U
U A A
A G C
U A A

36. Large and small
subunits of a
ribosome binding
with mRNA
Large Subunit
Ribosome
A U G
G U U
U A A
A G C
U A A

37. Large and small
subunits of a
ribosome binding
with mRNA
Large Subunit
Ribosome
A U G
G U U
U A A
A G C
U A A

38. Large and small
subunits of a
ribosome binding
with mRNA. The
polypeptide chain is
forming.
Large Subunit
Ribosome
A U G
G U U
U A A
A G C
U A A

39. Large and small
subunits of a
ribosome binding
with mRNA. The
polypeptide chain is
forming.
Large Subunit
Ribosome
A U G
G U U
U A A
A G C
U A A

40. Large and small
subunits of a
ribosome binding
with mRNA. The
polypeptide chain is
forming.
Large Subunit
Ribosome
A U G
G U U
U A A
A G C
U A A

41. Large and small
subunits of a
ribosome binding
with mRNA. The
polypeptide chain is
forming.
Large Subunit
Ribosome
A U G
G U U
U A A
A G C
U A A

42. Large and small
subunits of a
ribosome binding
with mRNA. The
polypeptide chain is
forming.
Large Subunit
Ribosome
A U G
G U U
U A A
A G C
U A A

43. Large and small
subunits of a
ribosome binding
with mRNA. The
polypeptide chain is
forming.
Large Subunit
Ribosome
A U G
G U U
U A A
A G C
U A A

44. The ribosome stops
translation when it
reaches the stop
codon.
Large Subunit
Ribosome
A U G
G U U
U A A
A G C
U A A

45. The ribosome stops
translation when it
reaches the stop
codon.
Large Subunit
Ribosome
A U G
G U U
U A A
A G C
U A A

46. The amino acid
strand folds into a
tertiary structure.
Large Subunit
Ribosome
A U G
G U U
U A A
A G C
U A A

47. The amino acid
strand folds into a
tertiary structure.
Large Subunit
Ribosome
A U G
G U U
U A A
A G C
U A A

48. The amino acid
strand folds into a
tertiary structure.
Large Subunit
Ribosome
A U G
G U U
U A A
A G C
U A A

49. The amino acid
strand is made into
a protein.
Large Subunit
Ribosome
A U G
G U U
U A A
A G C
U A A

50. Summary
• A summary of protein synthesis is the
information on DNA is copied onto an mRNA
strand, which then leaves the nucleus and
goes into a ribosome. Then, in the ribosome, a
tRNA molecule brings an amino acid that is
coded for by codons on the mRNA. Amino
acids are bonded together as the mRNA
moves through the ribosome. Amino acids
joined together make a protein, which is why
it is called protein synthesis.