1. Translation
mRNA  protein

2. Remember…
During transcription, mRNA is copied from a strand of DNA in the nucleus.
mRNA contains the instructions (code) for making a protein.
The mRNA then leaves the nucleus to find a ribosome in the cytoplasm.

3. mRNA

4. Translation
Translation is the process of making a protein from the mRNA code (protein synthesis).
Translation takes place on a ribosome in the cytoplasm.
Ribosomes are made of proteins ribosomal RNA (rRNA).

5. Steps of Translation mRNA attaches to a ribosome.
Translation begins at AUG, the start codon.

6. Steps of Translation
3. The tRNA (transfer RNA) molecule with the correct anticodon attaches to the mRNA and brings along an amino acid.

7. Translation
4. The ribosome forms a bond between the amino acids from each tRNA which forms a polypeptide chain.
Polypeptide chain

8. Translation
5. The ribosome then releases the amino acid and the tRNA floats away.
6. The ribosome moves along the mRNA to the next codon binding new tRNA molecules and amino acids.

9. Translation
7. When the ribosome reaches a STOP codon, it releases the chain of amino acids (protein) and the mRNA strand.

10. Translation Animation

11. The Genetic Code
How is the order of the bases on an mRNA strand translated into a protein?

12. The Genetic Code
The genetic code on the mRNA is read three letters at a time by a ribosome
This 3-letter “word” is known as a codon.
Each codon translates to one amino acid.

13. The Genetic Code

14. The Genetic Code
There are 64 possible 3-base codons that code for 20 different amino acids.
A codon chart is used to translate an mRNA codon into an amino acid.
There are 2 types of codon charts. Know how to read both!

15. Codon Chart

16. Codon Chart
To read the square chart, Find the row of the amino acid by finding the letter of the first base on the left-hand side.
Then find the column by locating the letter of the second base (top of chart)
Then find the letter of the third base on the right-hand side.

17. Codon Chart
What amino acid does AGU code for?
Serine

18. Codon Chart
What amino acid does ACG code for?
Threonine

19. Practice-Protein Synthesis
DNA: T A C T G G C C T T C G
mRNA: ___________________
*Use a codon chart
a.a.:______________________
A U G
A C C
G G A
A G C
Start-
Threonine-
Glycine-
Serine

20. To sum it all up:

22. Protein Synthesis Transcription Translation In the nucleus
In the cytoplasm (ribosome)