Protein synthesis 2

focus on translation

Ribosome

* 2 subunits, one large and small


* E, P, and A site
* **E site**: releases tRNA molecules
* **P site**: holds onto one aa-tRNA and growing chain of amino acids
* **A site**: holds tRNA bringing the next amino acid
* A, P, E order
* arrival, projection, ejection

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Steps

1. Initiation
2. elongation
3. termination

Initiation

1. start codon reaches the P site
2. tRNA attaches to the start codon
3. find the codon which tells us what amino acid attaches to the anticodon (tRNA)

Start Codon

AUG

mRNA

is the __codon__, tRNA is the __anticodon__.

Elongation

1. A site gets an anticodon that attaches with the matching nucleotides
2. both amino acids attach to each other with a peptide bond
3. ribosome moves down, the tRNA gets to the E site, and gets ejected

Termination

1. A site reaches a STOP codon
2. a release factor binds to the A site
3. release factor cuts the protein off from the mRNA
4. goes to the Golgi apparatus to be folded