1. Translation AKA, Protein Synthesis Amino Acid Protein tRNA Nucleus
mRNA
Ribosome
(rRNA)
Translation
AKA, Protein Synthesis

2. Definition of Translation
The process where ribosomes and RNA build proteins following the instructions from DNA
RNA  Proteins
All three types of RNA must work together for translation to occur

3. Purpose of Translation (WHY it happens)
Translation occurs in order to build the thousands of different proteins needed by the cell to function properly
The amino acids that make up proteins must be connected in the correct order to make sure that the protein has the right shape to function properly
The genetic code in DNA simply gives the order of the amino acids
Look! This answers the question about why AAs need to be in the right order!

4. When, Where, Who All the time!
At the ribosomes (both free in the cytoplasm and attached to the ER)
Every living thing!

5. Steps in Translation (the HOW!)
Transcription builds mRNA
mRNA joins Ribosome
Ribosome reads mRNA Codons
tRNA brings Amino Acids to Ribosome
tRNA Anti-codons base pair with mRNA codons inside ribosome
Ribosome makes Peptide Bonds that join Amino Acids in a chain
Processes # 3,4, 5, & 6 Repeat
Completed Protein released at Stop Codon

6. Step 1: Transcription
mRNA is made in the nucleus by transcription – only one gene is copied at a time, which gives mRNA the code for one protein (the central dogma)

7. Step 2: mRNA joins Ribosome
mRNA leaves the nucleus through the nuclear pores, and joins a ribosome (it fits between the large and small subunits of the ribosome)
(mRNA)
(rRNA)

8. Step 3: Ribosome reads Codons
The ribosome “reads” the mRNA message one codon at a time
A codon is a group of 3 nucleotides on mRNA that carries the code for one specific amino acid
Did you find the codon definition and an example?
First codon = AUG
Second codon = GCA
Third codon = …

9. Step 4: tRNA brings Amino Acids
Each tRNA molecule carries a specific amino acid with it
There are 20 different amino acids, and each tRNA can only carry one kind of amino acid
The amino acid it has depends on the tRNA anti-codon

10. More accurate diagrams of transfer RNA….

11. Step 5: tRNA Anti-codons Base Pair with mRNA Codons
tRNA with an anti-codon that matches the mRNA codon joins the ribosome
The bases in the mRNA codon must pair with the bases in the tRNA anti-codon to make sure that the amino acids are in the correct order
Look! All 3 kinds of RNA working together!
Can you write your own anti-codon definition and give an example?

12. tRNA Anti-Codons pair with mRNA codons inside ribosome

13. Step 6: Peptide Bonds join AAs
The rRNA connects the new amino acid to the other amino acids by a peptide bond
This forms a chain of amino acids that grows longer and longer
The incomplete chain of amino acids is called a polypeptide – when the entire chain is completed it will be a protein
Use this info to compare:
1. amino acids vs.proteins 2. polypeptides vs. peptide bonds

15. Step 7: Process Repeats The process repeats over and over:
The used tRNA leaves the ribosome to get another amino acid
The ribosome moves along the mRNA to the next codon
Another tRNA brings the next amino acid
mRNA codons bond with tRNA anti-codons
rRNA forms a peptide bond between AAs
And so on….

17. Step 8: Completed Protein Released
Eventually, the ribosome reaches the end of the mRNA
The last codon should be a “Stop” codon
This signals the ribosome to release both the mRNA and the protein
The mRNA can join another ribosome and build another protein
The protein goes to do its job!